Updated  24 January  2014



















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Massed fire means the fire of two or more batteries against a single target.  The original British term for massed fire is a concentration, although in the second half of the 20th Century the term ‘multi-battery mission’ was adopted.  Originally it meant two or more batteries with their pivot guns aimed at the same point, and the other guns of the battery having their line of fire parallel to their pivot gun.

The target could be ‘impromptu’, later called 'opportunity', meaning that it had not been anticipated and planned for, or ‘planned’.  Several planned targets could be engaged simultaneously or in succession and called ‘programme shoots’, later a ‘fire plan’, usually as part of as part of a combined arms operation. 

The basic gunnery within a battery is generally unaffected by massing the fire of many batteries, although extra checks against errors were often made.  However, massing fire has other elements: someone with the authority to order it, and the processes and communications to be able to do it rapidly and efficiently.


Before indirect fire, concentrating artillery fire meant concentrating the guns in one place, Napoleon’s ‘grand battery’ being an example.  Concentrating the guns by co-locating them so that they could concentrate their fire against particular parts of the defences during a siege was long established in siege warfare. 

The introduction of indirect fire provided ‘fire-power mobility’.  This enabled fire of a battery to be used against widely separated targets without moving the battery.  The corollary of this was that fire of several different batteries could be concentrated on one target without moving the guns to a position where they could see the target.  However, this meant having appropriate techniques and procedures, particularly for impromptu targets and the need for a very speedy engagement.  Planned targets where there is time for planning and preparation is a far easier problem.

In the direct fire era the battery commander was with his guns and directed their fire.  This recognition that the battery commander was responsible for the tactical fire control of his battery continued with the adoption of indirect fire.  Therefore the field battery commander’s position in action was forward where he could see the targets, not with his guns.  It was also British practice, in the early 20th century, that the battery commander determined the firing data – range, switch angle from the aiming point and if necessary angle of sight and fuze setting for his guns, another carry-over from direct fire.  The guns made some individual corrections to this data if necessary, there was no intermediate technical fire control between the observer and the guns, at least for the field artillery.


Before 1914 artillery fire was expected to be against impromptu targets in a meeting engagement or against well prepared fortified defences.  This was the long-standing pattern of warfare although the size and space of operations was increasing.  Guns were used under the tactical control of their battery commander, although he could deploy an ‘observing officer’, one of his battery’s subalterns, to the battery's Observation Post (OP) if necessary.  However, massed indirect fire was emerging.

‘Brigade control’ was possible, a brigade being a lieutenant-colonel’s command of usually three batteries.  However, brigade control meant having all the battery commanders together where they could see the target, and each ranged (adjusted) his battery’s fire onto the brigade target.  The position of a divisional Commander, Royal Artillery (CRA) had only been established in 1907 and the notion of ‘divisional control’ did not find its way into official publications.

There was another method for concentration, Field Artillery Training (FAT), 1912 and 1914, required battery commanders (BCs) to prepare sketches (panoramas) of enemy positions as viewed from their OPs, two copies were sent to the field artillery brigade commander who lettered prominent common points on the battery's sketches and sent one of the copies back to the BCs.  This enabled the brigade and battery commanders to identify common points, decide which battery was best able to engage it or whether all batteries could be concentrated on a point.

However, FAT not giving the matter great attention was not the end of it.  Bethell in his Modern Artillery in the Field, 1911, in discussing artillery versus artillery identified massed fire.  He suggested that when gun to gun ranging was impossible “massing the fire of dispersed batteries upon each hostile battery in turn is likely to be more effective than letting each battery fire at the one opposite it.”  He also stated “Massing the fire of dispersed batteries has now become a fine art, and in a deliberate action, when the fire-commander’s panorama sketches have been prepared, and telephone communication established, the C.R.A. can bring an enormous volume of fire upon any desired point.  This system has, however, its practical limitations, and is by no means an universal panacea for success.”  However, a change in training requirements meant that it was not included in subsequent editions of FAT.

At this time there were no methods for routine predicted fire.  Communications were also limited, either visual (flags or lamps) or field telephone (and cable laid from the observation position to the battery).


Once the front had stabilised, World War 1 revealed little need for brigade (or higher) control against impromptu targets.  However, targets were generally small (wiring or working parties and the like) and well within the capabilities of a single battery.  The initial advance to and retreat from Mons was too fast to lay much telephone cable and direct fire tended to be normal.  Furthermore, because the observer was responsible for producing firing data, ranging more than one battery was generally impractical.  Nevertheless by late October 1914 some artillery commanders were making some use of massed fire, although telephone communications were still limited, but by the end of 1914 telephone networks developed rapidly.

The war quickly showed that BCs could not spend their entire time at their battery’s OP, the other officers of the battery relieved the BC as observing officer and acted with the BC’s authority.  The Catechism for Artillery Officers (the RFA and RGA versions both said the same on this matter), issued by GHQ in March 1918 stated “Do you thoroughly appreciate the fact that, whoever is watching from the battery O.P., be it the B.C., or any of the Battery H.Q., he is nominally commanding the battery, and must call it into action instantly if necessary, get it shooting, and then make his report?”  Reference to 'nominally commanding' highlights that tactical fire control was the key function of command.

However, while a single battery’s fire was appropriate against small impromptu targets, programmed bombardments soon became important.  Broadly, these fell into three categories:

Nevertheless none of these necessarily involved a single observer controlling the fire of several batteries simultaneously against a target.

The barrage and other programme engagements were only usable in the initial hours of an offensive.  Standing barrages were planned to deal with counter-attacks, and had to be called when needed.  The difficulty was the tenuous communications available to the forward observing officers accompanying the attacking infantry.  The communications limitations made impromptu targets very difficult and fire by massed batteries against impromptu targets a practical impossibility.

Aerial observation soon became important because it was the best means of finding and engaging targets some distance beyond the front line, notably hostile artillery.  Typically these would be engaged by a zone call from the air observer and could be ranged.  However, they were usually single battery targets, but when guns from several batteries were used each battery was individually ranged.  Furthermore, air observers (RFC and later RAF) did not have formal tactical fire control authority, they reported targets and their observations of fall of shot, they did not give orders, even though some pilots were artillery officers. 

Nevertheless, massed fire was potentially a little easier with an air observer because firing data was calculated in the battery (usually the target was on a Target List) and the aircraft pilot or observer reported observations of the fall of shot using the ‘clock-ray’ method relative to north.  These observations were converted into firing data by the BC or another officer on the gun position, in RGA batteries after the first few months of war the BC was were less likely to be at the OP, and if aerial observation was being used he needed to be at the battery position, not least because the aerial observer reported observations and the battery commander had to decide when to start fire for effect and how much fire to deliver.

Communications between air observers and batteries increasingly used wireless, which had been used on exercises in 1912.  Mostly wireless was one way, from aircraft to ground using Morse code and what became the 'artillery code', a set of two and three letter abbreviations.  If the battery needed to tell the air observer something then visual signaling was used, white marker strips on the ground using a symbolic code.  However, two way radios became available towards the end of the war but were only used for air observation of targets in depth, well behind the position of most hostile batteries except the most long ranged.

There was some massing of counter-battery fire.  By 1917 two batteries (heavy howitzers) were sometime used by an air observer, basically they fired alternately.  The reason for this concentration was to maximise the number of observed rounds during the aircraft’s flight duration, an early type of ‘rotation shoot’. 

However, later that year concentrations became quite widely used for counter-battery fire.  These concentrations involved several RGA batteries (heavy howitzer fire was the preferred weapon), controlled by a corps’ Counter Battery Staff Officer (CBSO).  The batteries had the target location and engaged it together using map shooting (predicted fire) techniques.  This fire was against known batteries in response to a ‘guns now firing’ report, usually from an air observer, but also sound ranging or flash spotting.  These were not impromptu targets because they were known and registered, and engaged in accordance with standing orders from an artillery commander.  

GHQ Artillery Notes No 3, Counter-Battery Work, February 1918, explicitly gave the CBSO 'executive control', this appears to be the first time that centralised 'control' of artillery fire was formally separated from its 'command', it was a critical innovation.  However, it seems to have lapsed in the inter-war years but re-emerged in WW2.

Of course the most notable use of massed fire was a barrage.  These could only be programmed, not impromptu, and target details were issued on specially printed maps, which the batteries used to calculate their firing data.  Before Cambrai in late 1917 key points in a barrage were always ranged and registered.  Thereafter they were usually predicted (map shooting).  However, in gunnery terms barrage fire was not ‘concentrated’, each gun in a battery had its own aimpoints on successive lines of the barrage, although several batteries could be firing at the same part of each barrage line.  Nevertheless concentrations, particularly in bombardments, could be used in the programme shoots of which the barrage was part; although to neutralise hostile batteries ‘de-concentration’ was often use – several batteries of 6 howitzers could each simultaneously attack six separate hostile batteries.  Barrages were used both for offensive firepower and defensive.


Field Artillery Training Vol 2 Gunnery (Provisional) 1921, reflected the lessons of the war and stated that concentration of fire was a principle applicable to many situations.  However, it cautioned against a ‘haphazard rain of projectiles’ and required each battery to be assigned a portion of the target or a lane or area.  Concentrated fire was always to be opened simultaneously at an intense rate by all participating batteries to achieve surprise and greatest moral effect.  It did not give any methods or techniques for doing this against impromptu targets. 

The 1923 and 1928 editions of FAT Vol 2 Gunnery had nothing to say on the matter and the 1928 edition of the new Vol 3 Organization & Deployment merely stated that concentrations were used when an enemy position was known in detail.  The implication being that they were not used against impromptu targets.

However, AT Vol 2 Gunnery 1934 returned to the matter of brigade control and programme shoots.  Concentrations could be achieved by the field artillery brigade commander indicating targets to the BCs collectively or individually.  Engagement could be by:

The introduction of the new regimental organisation in 1938, and associated instructions in Military Training Pamphlets (MTP) 10 and 17 for field and medium regiments did not address procedures for regimental or larger concentrations against impromptu targets, AT 1934 remained in effect.  The new organisation divided each battery into three (field regiments) or two (medium regiments) troops each deploying a short distance apart.  Each troop having its own command post, the observer remained responsible for ordering the switch from the zero line and the range.  There was also a battery command post. 

This meant that troops’ fire had to be massed if the target was for the entire battery. Only one troop did the ranging, the one commanded by the troop commander that ordered the engagement.  Therefore there had to be a means of providing corrected switch and range to the other troops in the battery, a process called 'linked shooting’. The MTPs provided two Methods, A and B, for link shooting.  They used new instruments, the DW Plotter or rapporteur.  The two Methods differed in where the control troop’s firing data was converted, either by the control troop’s CP or the linked troops’ CPs.  See 1938 Reorganisation on the Between the Wars 1919–39 page for more details.


The MTPs were superseded at the beginning of 1940 by Supplement 1 to Artillery Training Vol 2 Gunnery 1934.  This supplement dealt with technical processes in batteries, including for programme shoots and regimental concentrations, with each troop aiming its pivot gun at the centre of the concentration.  An effective concentration required all the guns to be on a common survey 'grid' for orientation and fixation.

Preparations for opening fire were progressive, first each troop became ready, having oriented their guns and fixed the position of their pivot gun.  Next the battery command post officer brought the troops onto battery orientation and fixation.  This included preparation of the battery shooting trace, with the positions of the pivot gun of each troop, being issued to each troop for their artillery board.  A copy of this trace was also provided to the other battery enabling each battery to prepare a regimental shooting trace.  Battery directors, and hence zero lines, were also synchronised. 

When this was completed all troops of the regiment could shoot together at whatever targets were within their range.  The concept was to enable link shooting procedures at regimental level, whereby one troop, ranged the target as the ‘control troop’ then provided the switch from the regimental zero line for each of the other troops in the regiment.  The methods for doing this were the same as they were for the troops in a battery. 

A regimental concentration against an impromptu target was used successfully at least once during the campaign in France in 1940.  However, in July a new pamphlet appeared New Procedure for Lines of Fire, Fixation and Fire Control.  This simplified procedures and replaced the DW Plotter and rapporteur with the ‘window method’ and No 4 Fan for link shooting, see Lessons from France on the World War 2 1939-45 page.  by late 1940 field regiments starter reorganising from two batteries each with three troop, to three batteries each of two troops, although it took over two years to form all the third batteries.

It also dealt, very briefly, with regimental concentrations, stating that they should only attempted on very large area targets until the survey party had placed all six troops on a common survey grid.  Concentration could be by a map reference (grid reference in modern terms) obtained from the map or from shooting by one troop.  Concentrations could only be ordered by regimental HQ, the map references and necessary orders being transmitted to battery CPs who passed them to their troop CPs. 

This meant that either concentrations relied entirely on predicted fire, or the ranging troop had to convert their firing data to a map reference, presumably without removing the correction of the moment data.  The implication was that link shooting hadn’t worked well at the regimental level, possibly because it involved six troops and this was too many, although it's not clear why this should be. 

Nevertheless it seems to have been becoming clear that there was a real need for rapid regimental if not larger concentrations against opportunity targets.  During 1941 Brigadier HJ Parham, CRA of 38 Infantry Division in UK developed a new approach.  It’s unclear if it was his own initiative (quite possible, his regiment had successfully engaged an opportunity target with all its guns in 1940) or if the matter had been discussed among senior artillery commanders and he agreed to develop a solution. 

Improving radios was almost certainly an enabling factor.  Despite the increasing distances between observers, guns and HQs, the new generation of HF radios (No 19, No 22) were powerful enough to enable a forward observer to communicate directly with divisional HQ.  Effective communications procedures were the key factor and radio enabled simultaneous communications with several stations without 'setting-up' a call, an impossibility with normal line circuit layouts.  Simultaneity was important for speed of response and the artillery fire orders practice of one station repeating the fire order to enable the originator to confirm they had been correctly received and other stations getting two chances to hear them and then to acknowledge them (or ask for their repetition if they hadn't).

Parham realised that some dispersion of battery mean points of impact was a good thing in large concentrations because it meant a larger area was effectively engaged.  More shells meant there were more splinters that added together increased the effective distance of fire from the bursts.  Dividing the target area into areas for each battery or regiment, as the pre-war procedure had suggested, was unnecessary.

The solution was to apply the same range and line correction ordered by the observer to the ranging battery to all the other batteries.  These corrections were ordered in yards for both line (azimuth) and range (normal battery procedure was a switch in degrees and minutes for the line correction).  However, this procedure ignored the fact that the line correction was relative to the ranging battery’s line of fire, which was different to that of the other batteries, Figure 1 shows the implications.  Nevertheless 38 Division developed and proved the procedures for concentrations of up to six regiments (144 guns) under divisional control.

Figure 1 – Effect of Identical Corrections

Corrections error


However, a large demonstration before a galaxy of senior officers at Larkhill almost led to disaster.  Members of the audience were invited to select targets and range them.  Unfortunately the corrections accumulated, as spectators were invited to move the fire around at new targets, and the number of batteries involved and their dispersion meant that eventually some rounds fell among the red hatted audience. 

Fortunately there were no casualties, but the procedures obviously needed refining.  Applying a particular battery’s corrections to all batteries wasn’t acceptable.  However, area fire did not need notable precision so bracketing the target was deemed unnecessary.  Instead the observer ordered a cardinal point bearing (North East, South, etc) and a distance in yards from the observed fall of shot to the target.  This could be safely applied by all batteries and, most importantly, easily plotted in their CPs. 

The new procedure was approved, in RA Training Memorandum (RATM) No 6, in September 1942.  This meant that 1st Army, including 1 and 2 AGRA, where Parham was then BRA, could be trained before their invasion of Algeria; but almost certainly meant that 8th Army was not fully trained until the N African campaign was over.  That said Montgomery seems to have been aware of the new procedures, he had been GOC-in-C South-Eastern Command in England, when he took command of 8th Army in mid-1942 insisting that artillery returned to concentrating its firepower and ditch the bad habits it had acquired in N Africa.  It's also likely that the procedures were in use in UK before RATM 6 was published and hence regiments sent to N Africa were familiar with them.

RATM 6 dealt with regimental and divisional concentration.  It identified the two essentials for effective concentration of fire as:

It also identified two situations for concentrations: where a particular observer had been sent forward in anticipation of concentrations being required, or where a normal observer identifies a target as worth a concentration and in effect requested the fire of the regiment from regimental headquarters.  The second was not applicable to divisional concentrations, in the first such observers were described as ‘authorised’, and for divisional concentrations they were called the ‘Commander’s Representative’.   Air OPs could also be authorised.  In all cases fire could either start at fire for effect or the target could be ranged.  When ranging one gun, normally from the observer's own troop, would be used and the corrections applied to all guns.  

Authorised observers had to be on the regimental (including regimental HQ and all battery CPs) or divisional (HQRA and all regimental HQs) artillery wireless net (frequency), depending on their authority.  An authorised observer was able to order fire directly to the batteries if he was authorised, or to regiments if he was a CRA's representative only the senior station repeated back the fire order, regimental headquarters or HQRA remained silent.  

 The authorised observer sent his fire orders to the regiment's Command Post Officers (CPO) on the regimental net and they passed them to their battery's Gun Position Officers (GPO) at their troop command posts.  Divisional procedures were similar, the Commander's Representative sent orders on the divisional wireless net to all the regimental headquarters, each resent them on their regimental nets to the CPOs who passed them to their GPOs.   

Unauthorised observers had to request fire from their regimental headquarters, which was run by the adjutant who allocated batteries and ammunition.  The observers were on their troop net, and the GPO passed it by line to the battery CPO who established an omnibus line circuit to the adjutant and all other CPOs or used the regimental wireless net.  The CPOs passed the orders to their GPOs.  

Examples of these fire orders are at Fire Discipline.

The target location was usually ordered as a map reference, with a target number (eg 'Uncle 5') for a divisional concentration.  A regimental concentration was ordered as ‘Monkey Target’ (the old phonetic alphabet).  For a regimental concentration the amount of ammunition was ordered in the normal way - ‘nn Rounds Gunfire’. However, for divisional targets the number of rounds was ordered as ‘Scale 5’ (or whatever number of rounds).  This meant that each gun fired the ordered amount, but if any guns or batteries were missing or engaged on other tasks the guns that were available fired more to make up for the missing ones.  Regimental HQs and battery CPs were responsible for managing the compensating fire.

The observer decided whether to open at gunfire or to range the target.  If it was to be ranged then the observer ordered ranging in his initial orders, each troop CP produced firing data and reported ‘ready’ when it had a section (2 guns) ready to fire.  The first troop to report ready was normally given the ranging task on behalf of all other guns.  Of course troop CPs reported to their battery CP, and for a divisional concentration the battery CPs reported to their regimental HQs, which then reported to the observer. 

 In February 1943 Parham reported from N Africa to HQ DRA in London:

In the section dealing with concentrations in RATM No 6 also introduced 'Quick regimental fire plans' with the purpose of providing a simple and quick fireplan to neutralise actual or suspected enemy positions in support of an infantry battalion attack.  This was an extension of the concept of an authorised observer, although this observer was expected to be a battery commander, regimental second -in-command or even the CO himself, co-located with the supported battalion commander where they could see the targets.

The following year these procedures became part of a new pamphlet, Artillery Training Vol III, Pam 3, Part III Concentrations of Observed Fire.  By this time the new phonetic alphabet was used (Mike instead of Monkey) and the opening wireless call was triplicated as a means of creating a sense of urgency and ensuring it was heard among recipients - “Mike Target, Mike Target, Mike Target”.   

A new edition of the pamphlet replaced it in early 1944, Artillery Training Vol III, Pam 12 Concentrations of Observed Fire.  It included instructions about using the artillery board and two plotting methods.  These were a locally made talc (clear celluloid) romer shaped as an isosceles triangle with distance scales on each side, and a six arm trace of the points with distance scales on each arm.  It introduced two more types of concentration:

However, it seems that CAGRA and CCRA representatives may have been used, although occasionally artillery commanders represented themselves.  The authorisation process was the same as that used by unauthorised observers for regimental and divisional targets.  Some accounts refer to Whisky targets, ie Army level.  The problem was that an Army did not have an artillery commander, the Brigadier RA was a staff officer and did not have command authority.  Nevertheless it would be possible for one CCRA to request fire from his neighbours and AGRAs were assigned to support corps.

The 1944 pamphlet also included Linear Concentrations called Stonks.  This term had been unofficially adopted earlier in the war with various meanings.  The 1944 stonk was 525 yards long, with all guns aimed at their specific aimpoints along this line, which had an ‘axis’, a grid bearing ordered by the observer.  Each regiment covered the full length of the linear, a field regiment having 16 aimpoints for its 24 guns while medium and heavy regiments had 8 for their 16 guns.  Stonks were not ranged.

Figure 2 - Command Post Protractor

Used in battery and troop CPs, with cardinal point plotting trace and Stonk templates below it.  Field and medium templates are for troops (A-F), for heavy they are batteries.

Of course there was a prerequisite for effective concentrations – survey.  All troops had to be surveyed on a common grid with the same orientation.  Furthermore if predicted fire was used then this common grid had to be the same as that used for the target.


Concentration procedures remained generally unchanged until the mid-1960's although evolutionary changes in technical fire control processes, see Fire Control after WW 2, affected them.  The term ‘Commander’s Representative’ was gradually dropped in favour of ‘authorised observer’, and any artillery observer could be given this authority for a short or extended period of time.  Observers without authority were ‘unauthorised’ but could request fire from the regiment’s adjutant or through him to the division’s Brigade Major RA.  The types of relationship between artillery and other arms were also expanded.  'Under Command' and 'In Support' had been used for many decades, to them were added 'In Direct Support' and 'At Priority Call'.  The latter seems to have be created primarily  with the CBO in mind, in effect it made a person with this authority 'super-authorised', in that batteries could be taken from other tasks.

The one significant change was the introduction of Target Grid Corrections (TGC) in 1950, replacing Cardinal point corrections.  In this the observer normally ordered corrections to the fall of shot relative to the line from himself through the target, the 'Observer - Target line'.  This simplified gunnery because TGC were used when ranging any number of guns, not just large concentrations. 

However, post-war procedures also provided guidance about the size of area that could be covered by effective fire (not the same thing as all rounds falling within the area!).  These were 150 yards diameter for a battery, 250 yards for a regiment and 350 yards for a divisional artillery.  These dimensions seem to have originated in the Canadian artillery in 1945.  They reflect some spread between battery mean points of impact and that more guns firing meant that there was an effective splinter density at a greater distance.

The Quadrilateral ABCA procedures were adopted in the mid-1960's and formally published in AT Vol III, Pam 11, Part 2 1969 Duties in Action.  They officially recognised two systems of tactical fire control.  System 1 observers, (eg the US Army and Marines), could only request fire from a Fire Direction Centre.  System 2 observers (eg Australia, Canada, UK) could be authorised to order fire, this authorisation was standard procedure for an observer and his own battery, and an observer could be authorised to order larger concentrations.  However, the ABCA procedures did not include the use of ‘Mike Target’ etc or ‘Scale’. 

Authorised observers ordered or ‘ordinary observers’ (the term changed) requested ‘Fire Mission Regiment’ or ‘Fire Mission Division’ and if authorised ordered the amount to be fired eg ‘5 Rounds Fire for Effect’.  Of course authorised observers would usually have a permitted maximum for a fire mission, ordinary observers were told how much ammunition they could use when they were allocated fire units by the adjutant or BMRA.

The quick regimental fire plan promulgated in RATM 6 also evolved to include both programmed and 'on-call' concentrations, and smoke screens.  After the war they became standard.  It essence it meant that a battery commander was allocated control of his regiment and an ammunition allocation for a period, and the battalion’s mortars to support a battalion quick attack.  Typically he had about an hour to design a fire plan as part of the infantry commander’s plan, select targets, issue orders to the guns and his observers, who adjusted some targets in sufficient time to enable target information to be distributed among the batteries.  It was quite challenging, particularly before computers did the ballistic calculations.  The plan might include concentrations of two or more batteries, targets on a timed program and targets on-call, the latter being engaged by battery(s) superimposed on other targets.

By the late 20th Century the system had evolved.  A battery commander could be allocated several batteries and ammunition for a period of time.  This might be used for a fire plan or for opportunity targets.  In the latter case he would authorise his battery observers to use a number of batteries against opportunity targets or to support company tasks.  The battery commander managed conflicting demands in consultation with the supported commander.  By this time the observer ordered or requested a specific number of guns for a fire mission.

The underlying principle has remained the same for a century.  Artillery commanders are responsible for tactical fire control.  However, recognition that command and control can be separated (which emerged in 1917 with the creation of the Corps Counter Battery Staff Officer with executive authority to order fire) meant that authority to order and control fire could be placed wherever it was needed.


Colonel HA Bethell RFA (Retired) Modern Artillery in the Field, 1911.  In WW 1 he became CRA of 25 Division.



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