Spell the plural of an acronym consistently without apostrophe

Opinions differ on how to pluralize acronyms[*], but let's be
consistent: say "BTUs", not "BTU's".

[*] https://en.wikipedia.org/wiki/Acronym#Representing_plurals_and_possessives

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

info/Attacking.t

@@ -26,7 +26,7 @@ A combat has 15 steps:
 (12) Remove mobility from the aggressor's sectors/ship.
 (13) Possibly ask the aggressor for mil and units to move into the target.
 (14) Possibly interdict the aggressor's mil and units as they move.
-(15) Charge the aggressor BTU's.
+(15) Charge the aggressor BTUs.
 .FI
 .s1
 .L "(1)  Ask the aggressor for the target sector/ship."
@@ -339,7 +339,7 @@ stepping on land mines.  Note that there is no
 post-attack interdiction and no danger of stepping on land mines if the
 INTERDICT_ATT option is disabled (see version).
 .s1
-.L "(15) Charge the aggressor BTU's."
+.L "(15) Charge the aggressor BTUs."
 .s1
 The BTU cost is equal to 0.5 + (the total number of casualties) * 0.015.
 .s1

info/Citizens.t

@@ -44,7 +44,7 @@ If the thought of not being able
 to move conquered populace bothers you,
 then you have the option of converting these conquered people
 into uncompensated workers,
-involving the expenditure of BTU's and money
+involving the expenditure of BTUs and money
 (for the paperwork).
 If all the conquered people in one sector are converted to uw's,
 then the sector is then marked as yours.
@@ -58,7 +58,7 @@ You can get them back to work by heavy-handed military control
 Finally, your populace requires happiness to keep their enthusiasm
 for work going.  As technology and education increase,
 your work force expects to share in the increased levels
-by getting more consumer items (VCR's, BMW's, etc)
+by getting more consumer items (VCRs, BMWs, etc)
 represented by happy strollers.
 If you don't have at least one happiness point
 per two units of education,

info/Innards.t

@@ -233,12 +233,12 @@ check for plague progress,
 Bureaucratic Time Units
 .s1
 There is one further update that is not handled in the sector
-update routine; that is the update of bureaucracy time units (BTU's).
+update routine; that is the update of bureaucracy time units (BTUs).
 These are the numbers printed in brackets before the command
 prompt.
-Most commands given use BTU's, some use 1, some use 2 and some use
+Most commands given use BTUs, some use 1, some use 2 and some use
-more, making BTU's a vital commodity.
+more, making BTUs a vital commodity.
-The generation of BTU's is
+The generation of BTUs is
 dependent on the efficiency and the work force in the capital sector.
 (see info BTU).
 .s1

info/Interception.t

@@ -37,7 +37,7 @@ Enemy planes will be intercepted by up to 1 more interceptor,
 i.e. 1 plane will be intercepted by 2 (if available), 2 by 3,
 3 by 4, etc. The highest
 numbered planes intercept first. Incoming missiles will only be intercepted
-by ABM's
+by ABMs
 .s1
 Once the roster of attackers & interceptors is determined, attackers
 and interceptors dogfight. First escorts & interceptors fight,
@@ -114,8 +114,8 @@ chance to abort, and the defender won't.  If the attacker aborts, the
 mission is over.  Else, the attacker flies on to the next sector in
 his flight path, perhaps to have combat again.
 .s1
-.L ABM's
+.L ABMs
-ABM's do not use the normal combat procedure. They simply have a %
+ABMs do not use the normal combat procedure. They simply have a %
 chance of destroying an incoming warhead equal to their defensive value.
 .s1
 .SA "Plane-types, plane, fly, recon, bomb, range, mission, Flak, Planes"

info/Land-units.t

@@ -67,7 +67,7 @@ works pretty much like the load command for ships. (See info \*Qlload\*U)
 Units on ships can transfer supplies to/from the ships with the \*Qltend\*U
 command.
 .s1
-.L "HQ's & Building land units"
+.L "HQs & Building land units"
 .s1
 Like planes and ships, land units are built in special sectors. For land units,
 the sector is the headquarters sectors, designation !. Like other units,
@@ -106,7 +106,7 @@ gain efficiency.
 .s1
 Ships can repair themselves in any sector, and can use work from their crew,
 or from a harbor they are in. Planes can only be repaired in airports, and
-only use work from the airport. Land units can be repaired in HQ's or
+only use work from the airport. Land units can be repaired in HQs or
 in fortresses, and use the work of the HQ or fort. This means that front-line
 units in forts will repair themselves each update, assuming that the
 necessary materials and work are available. They can also gain efficiency

info/Novice.t

@@ -447,7 +447,7 @@ It is always a good idea to keep surplus goods in your warehouse.
 The end result is that you can set up your country to move your products
 around without you logging in.
 It also doesn't cost as many mobility points
-to move things as distribute, and it costs no BTU's!
+to move things as distribute, and it costs no BTUs!
 .s1
 .ce 3
 \*(iFSome Further Clarifications
@@ -536,11 +536,11 @@ It takes conventional forces combined with nukes to really do damage.
 (Of course I won't fool you either;
 it doesn't hurt to have a few nukes either.)
 .s1
-Beware of running low on BTU's.
+Beware of running low on BTUs.
 I will recount one story of a player on this site
-that was running low on BTU's.
+that was running low on BTUs.
 His enemies launched a nuclear attack and hit his capital!
-Unfortunately, he didn't have enough BTU's
+Unfortunately, he didn't have enough BTUs
 to redesignate a new capital.
 The moral of the story is that you should
 plan an alternate capital at some point in the game.

info/Options.t

@@ -7,7 +7,7 @@ You get tech bleed from all countries, not just allies.
 .L AUTO_POWER
 Power report is only updated automatically, at the update.
 .L BLITZ
-Players get infinite BTU's.
+Players get infinite BTUs.
 .L BRIDGETOWERS
 You can build bridge towers, which allow you to build bridges from
 them.

info/Overview.t

@@ -90,7 +90,7 @@ unless you are very careful,
 it's probably not a good idea to rely on these automatics.
 .in
 .s1
-Bureaucratic Time Units (BTU's)
+Bureaucratic Time Units (BTUs)
 .in +0.3i
 .s1
 To prevent the more fanatical Empire players
@@ -103,31 +103,31 @@ You can't log in again until the counter resets itself
 (usually at midnight).
 .s1
 The other control on the number of commands that you may issue
-are called ``Bureaucratic Time Units'' or BTU's.
+are called ``Bureaucratic Time Units'' or BTUs.
 A BTU is an arbitrary amount of bureaucratic bookkeeping that
 your government must spend to perform a certain function.
-Most commands that are not merely informative cost BTU's.
+Most commands that are not merely informative cost BTUs.
 .s1
-BTU's are generated by your country's capital.
+BTUs are generated by your country's capital.
-The more efficient your capital, the more BTU's that are generated.
+The more efficient your capital, the more BTUs that are generated.
-The number of BTU's also depend on the game's settings.. See the
+The number of BTUs also depend on the game's settings.. See the
 output of the 'version' command for an estimate of BTU generation speeds.
-However, you may have a maximum of 512 BTU's at any one time.
+However, you may have a maximum of 512 BTUs at any one time.
-And once your BTU's reach zero, you may not issue any commands
+And once your BTUs reach zero, you may not issue any commands
-that use BTU's.
+that use BTUs.
 .s1
-Three things to note about BTU's:
+Three things to note about BTUs:
 .in +\w'00)\0\0'u
 .s1
 .L 1)
-Since commands use up BTU's,
+Since commands use up BTUs,
 this limits the number of commands
 that a player may issue over a particular time period.
 This has the effect of preventing the Empire fanatic
 from overruning other players with less free time to log on.
 .s1
 .L 2)
-The build-up of BTU's is constant and does not depend on being
+The build-up of BTUs is constant and does not depend on being
 logged in.
 This allows players to participate when it is convenient rather
 than at some fixed time
@@ -163,7 +163,7 @@ Until you \*Qbreak sanctuary\*U,
 your country is effectively in stasis.
 Nothing will change until you actually log in and
 force a change
-(such as designating a capital to begin accumulating BTU's).
+(such as designating a capital to begin accumulating BTUs).
 .s1
 The absolutely minimal set of information pages you should read are:
 break, map, ann, wire, tel, read, expl, move, res, cen, dist, thresh, lev,

info/Time.t

@@ -33,6 +33,6 @@ as follows:
 .EX
 The first \*Q##\*U is the Elapsed Time today, in minutes.
 This number starts at 0 every midnight.
-The second \*Q##\*U is the number of BTU's remaining.
+The second \*Q##\*U is the number of BTUs remaining.
 .s1
 .SA "Innards, version, BTU, Playing"

info/convert.t

@@ -35,6 +35,6 @@ Number to convert : 22
  22 conquered populace converted in 2,2 (45)
 Total new uw : 180
 .FI
-Note that there is a cost of 0.01 BTU's per civilian converted
+Note that there is a cost of 0.01 BTUs per civilian converted
 in addition to the registration fee of $1.5 per conversion.
 .SA "Populace, Mobility, Occupation"

info/demobilize.t

@@ -5,7 +5,7 @@
 The demob command returns soldiers from the military
 back to civilian life.
 In addition,
-you have the option of placing the returning GI's
+you have the option of placing the returning GIs
 into the nation's active reserve.
 The active reserve provides a pool of available military
 for a small salary (usually the same amount generated by a civilian)

info/enlist.t

@@ -45,7 +45,7 @@ Number to enlist (max 397) : 22
 Total new enlistment : 180
 Paperwork at recruiting stations ... 3.6
 .FI
-Note that there is a cost of 0.02 BTU's per draftee in addition to the
+Note that there is a cost of 0.02 BTUs per draftee in addition to the
 basic cost of the command and enlistees use up some mobility in the
 enlistment process (see \*Qinfo Mobility\*U for the exact formula).
 .s1

info/list.t

@@ -4,7 +4,7 @@
 .SY list
 The list command gets you a list of currently legal commands
 with their associated BTU costs,
-(see \*Qinfo time\*U for description of BTU's).
+(see \*Qinfo time\*U for description of BTUs).
 This should not be confused with \*Qinfo {commands}\*U
 which generates a brief summary of each command.
 .s1

info/lload.t

@@ -9,7 +9,7 @@ Commodities (like guns, civs, food) can be loaded onto any unit capable
 of carrying them (to see what cargos a unit can carry, use the show command).
 .s1
 Some land units can carry extra-light
-planes (typically these are SAM's)
+planes (typically these are SAMs)
 .s1
 Some land units can carry other units
 .s1

info/spy.t

@@ -15,7 +15,7 @@ are those from which you are spying,
 (see \*Qinfo syntax\*U for format).
 Note: you can only spy from sectors that have military or land units in them.
 .s1
-Note that the number of BTU's consumed
+Note that the number of BTUs consumed
 is dependent upon the number of sectors into which you spy,
 e.g., a 5x8 area costs one full BTU.
 .s1

info/wipe.t

@@ -7,7 +7,7 @@ from the specified sectors.
 Note that this will have drastic effects on sectors
 that rely on distribution in any way, so use with caution.
 Also note that if you make a mistake,
-it can cost lots of BTU's to reverse the effects of a wipe.
+it can cost lots of BTUs to reverse the effects of a wipe.
 .s1
 .EX level #5
 .NF

src/lib/subs/detonate.c

@@ -70,7 +70,7 @@ detonate(struct nukstr *np, coord x, coord y, int airburst)
     struct nstr_item ni;
     int changed = 0;
 
-    pr("Releasing RV's for %s detonation...\n",
+    pr("Releasing RVs for %s detonation...\n",
        airburst ? "airburst" : "groundburst");
 
     getsect(x, y, &sect);