First here are alternate names for the same signs, useful to eliminate duplicates. The pages CuneiformSigns.org/SignList1.htm etc. attempt to keep to traditional names, therefore do not use exactly the same names as in the UTC proposal of February 2004.

Second are signs where name distinctions are needed. Third is a discussion of mergers of six or more signs yielding later KU, and etymological information distinguishing some of these as to their original component identities. Overlap of GAN2 tenu with SHE3 is also an issue for correct identification of signs.

AG or AK
BAN or PAN
KUL instead of NUMUN (PSL list had NUMUN.gunu, should it be KUL.gunu?)
ERIM or ERIN2
KAK or GAG
GAR instead of NINDA or NIG2
GIM instead of DIM2
GIN2 or DUN3 (distinct?)
GU or KUSHU2 (PSL list did have KUSHU2, only independently; distinct?)
GU4 will appear later instead of GUD (though I earlier corrected GU4 to GUD to match Tinney)
GUM or KUM
HA instead of KU6
HAR instead of HUR
HU instead of MUSHEN
KUG or KU3
LU instead of UDU (reverse this?)
PI or GESHTU
SAL instead of MUNUS
TAK4 instead of KID2
TUM instead of IB2
UD or U4
UH3 rather than KUSHU2
UMUN2 or UMUM (Krebernik)

Some names which better respect unities and immediate constituents
(but which need not determine encoding order, since that can reflect components rather than names)

MUL rather than AN AN AN (a cluster, not a sequence of independent signs)
NAB rather than AN AN (ditto)

TUR3 = NUN x LAGAR (as shown by the etymologically related older forms; not = NUN.LAGAR)
     The immediate constitutents of TUR3 x infixes are precisely TUR3 as a unit and the infixes; they are not NUN and (LAGAR x those infixes), since the latter do not occur (with one conceivable and marginal exception). The signs LAGAR x infixes use infixes which do not occur as infixes to TUR3.

UTUA2 = "DAG x KISIM5" (a unit even though not visually infixed; not = DAG.KISIM5) The same remarks apply here as to TUR3 above. KISIM5 x infixes occur only visually as part of UTUA2 x those infixes, KISIM5 x infixes are not immediate constituents of those signs.
HUBUR = "NUNUZ x KISIM5" (same remarks as above)

*

Signs which are distinguished from each other:

ERIN2 (= ERIM?) and PUR2 are distinct (unrelated in early forms, see Labat #393)

GIR3 is now distinguished from PIRIG

KU vs. DUR2 vs. TUG2 vs. NAM2 vs. SHE3 = ESH2 vs. ZI3 (all eventually merged as late KU)
SHE3 instead of "GAN2 tenu" in quite a number of signs, as shown etymologically, or as suggested by alternations with TUG2 etc.
MASH vs. BAR when infixed into containers, as suggested by etymologically related forms "Classical" etc. (questions here)

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At least a three-way distinction is needed for these

TUK or KAB Labat #309, Fara #473, ZATU #277 with further distinctions?
HUB2 Labat #88b, Fara #474
GUB3 Labat #88a, Fara #237, ZATU #236
Borger ABZ older distinct ##64, 65, maybe use GUB3 for DA.inversum left arm/hand?

HI vs. SHAR2 were originally distinct, later merged. If SHAR2 (large circle) was originally only in numbers, then we can keep that distinction, as Tinney appears to do in the PSL list (only SHAR2 and SHAR2 x U). Thus HI x (DISH or KIN or GAD or ASH) rather than SHAR2 x (those infixed signs).

The following three are distinct.
SHID, Labat #314a 'thumb'; 'to recount' (Labat #314 four distinctions, Ellermeier does not distinguish?)
PISAN2, Labat #314b (also as a container with infixed signs) (not yet in PSL list)
MEZ Labat #314c 'hero, man' (not yet in PSL list)
Also notice Labat #317 vs. #317a PISAN2 x A vs. SHID x IM, with different containers.

EDIN (two forms separated by Labat #168, the second incorrectly called the "gunu" form of the first ? If they are distinct, an additional sign name is needed to distinguish them)

The following is a four-way distinction for which the names need to be distinct. In particular, the third should not be named as the fourth. Later UNUG and simple AB merged.
UNUG (= AB.gunu, a true gunu ?)
AB
AB x ASH2
AB x KI (not yet in PSL list?)

Labat #555 ZUM is two distinct signs, note the dotted line dividing the oldest forms. Need an additional name to distinguish one of them.

Distinctions
KUR2 vs. PAP, and PUSH2 = KUR2+HAL not PAP+HAL (where is the citation for this one?)

Distinctions

DUG x ASH at least two
Z91a/b/c
Fara 561 vs. 562

AB2 and KISIM5 are distinct?

GISHGAL is URU x MIN, not URU x A. (PSL list has both container-infix signs)

UG5 is EZEN x BAD not EZEN x AN ? (PSL list has both container-infix signs?)

GI4 not GI.gunu (it is not typical .gunu in any case, the February UTC proposal distintinguished these)

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Sign names which are alternates (I corrected the concordance for a couple of these where my usage was not the same as Steve Tinney's -- haven't revisited this small group for their current status)

Where I have a different usage than the PSL list, and am not yet making changes:
NIN (should be listed as a single sign even if originated as SAL x TUG2 or SAL x NAM2)
BALAG (instead of DUB2) (Are they distinct?)
      (PSL has both independently, and both AB2 x BALAG and AB2 x DUB2)

Questions: Are these pairs distinct? PSL has both.
KISAL vs. PAR4 ? PSL has both, each only independently.

PSL has neither:
KUNGA or SHUHUB ?
KIBIR or GIBIL2 ?

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The KU family of mergers

This section was written in reference to the UTC proposal of October, 2003, and has not been significantly updated since the version of February, 2004, although as Steve Tinney indicated, additional distinctions were added there. The questions about etymological identity especially of some infixed and superimposed forms may remain, and will be addressed more comprehensively later. Examples are included below.

A distinction KAR2 (= "GAN2.tenu") vs. GAN2 may be valid as independent signs, where the rotation (.tenu) is not conditioned by context. But many of the instances of GAN2 when superimposed on another sign seem to really be simply that, and the sign is turned so that it will be most identifiable as a Gestalt, not confused with the wedges of the base sign? That is to say, the turning does not signify that GAN2.tenu was superimposed, but that simple GAN2 is. In fact, many of these may have been SHE3 (= ESH2), not GAN2 at all in origin. Sign names which apply to the full historical range may therefore need to be corrected from GAN2 to SHE3 or equivalent. Similar reasoning may be valid for DISH.tenu or ASH.tenu, under conditions we perhaps can state, or perhaps do not yet know?

The next six are all distinguished by Krebernik 1998, but are all merged in Labat #536. The PSL list as of early October distinguished TUG2, ESH2 (= SHE3), and KU. The name KU has at least sometimes been used to refer to the result of merging all of these in later cuneiform. For infixed signs belonging to these six, can we usually identify which original sign they go back to?

KU (one horiztontal inside rectangle, touches both sides)
DUR2 (one horizontal inside rectangle, touches only right side) (a seat?)
NAM2 (two horizontals inside rectangle, touch both sides)
TUG2 (two horizontals inside rectangle, touch only right side) (determinative for cloth)
SHE3 (many horizontals inside rectangle, touch both sides) (strip of cloth?)
ZI3 (many horizontals inside rectangle, the whole slanted or skewed left)

Here are the relevant sign names included in the PSL list.
To which of the six signs should these be assigned?

TUG2
TUG2 OVER TUG2
KU
KU OVER HI TIMES ASH2
ESH2
ESH2 TENU

GU2 TIMES SAL PLUS TUG2
GA2 TIMES HA PLUS LU PLUS ESH2

These two later merged as expected from the
developments of their infixed components (?< Ellermeier):
TAG TIMES TUG2
TAG TIMES KU

Are these two or three alternate names for the same sign,
or distinct early signs with later mergers?
(Labat #330; no early equivalents to disambiguate)
LU2 TIMES TUG2
LU2 TIMES ESH2
LU2 TIMES ESH2 TENU
DUB TIMES ESH2 (from the CDLI-Civil merged list. What is the attestation?)

There is only one example of SIGN x ESH2 in the combined CDLI-Civil list where the identity of the infixed component is one I can unambiguously recognize, namely this next one KA x SHE3.)
KA x SHE3 (is this the same as PSL KA TIMES ESH2 ?)

Fara and ZATU have the following
      (my tentative name for infixed sign, except as noted from ZATU):
DUG x NAM2 (name in ZATU .eps, no number?)
ZATU #513 SHE x NAM2
ZATU #449 SI x SHE3
Fara #497 TUM x SHE3 (or TUM x ZI3 ?)
Fara #145 DA x SHE3 (or DA x ZI3 ?)
Fara #622 URU x (TUG2 or some other textile sign?)
Fara #522 SAL x TUG2 or ZATU #400 SAL x NAM2 (Labat #556)
USH TIMES KU (from the CDLI-Civil merged list. What is the attestation? There is no other example of SIGN x KU in the concordance.)

EZEN x SHE not EZEN.$e$$ig
(I have no idea where this is, have a number 99 next to it in notes, must find it again)

I do not find signs in the concordance unequivocally analyzed as SIGN x DUR2, (For semantic reasons I have considered SAL x DUR2 instead of SAL x textile as a conceivable origin of NIN 'lady' or 'goddess', a woman who wears cloth vs. a woman on a seat / throne? But "considered" is as far as I can go here.)