Hi Milo,
I'm unaware of any other definitions of a point.
Below is an extract from GNU units 2.17's
/usr/share/units/definitions.units.
#
# Printing
#
fournierpoint 0.1648 inch / 12 # First definition of the printers
# point made by Pierre Fournier who
# defined it in 1737 as 1|12 of a
# cicero which was 0.1648 inches.
olddidotpoint 1|72 frenchinch # François Ambroise Didot, one of
# a family of printers, changed
# Fournier's definition around 1770
# to fit to the French units then in
# use.
bertholdpoint 1|2660 m # H. Berthold tried to create a
# metric version of the didot point
# in 1878.
INpoint 0.4 mm # This point was created by a
# group directed by Fermin Didot in
# 1881 and is associated with the
# imprimerie nationale. It doesn't
# seem to have been used much.
germandidotpoint 0.376065 mm # Exact definition appears in DIN
# 16507, a German standards document
# of 1954. Adopted more broadly in
# 1966 by ???
metricpoint 3|8 mm # Proposed in 1977 by Eurograf
oldpoint 1|72.27 inch # The American point was invented
printerspoint oldpoint # by Nelson Hawks in 1879 and
texpoint oldpoint # dominates USA publishing.
# It was standardized by the American
# Typefounders Association at the
# value of 0.013837 inches exactly.
# Knuth uses the approximation given
# here (which is very close). The
# comp.fonts FAQ claims that this
# value is supposed to be 1|12 of a
# pica where 83 picas is equal to 35
# cm. But this value differs from
# the standard.
texscaledpoint 1|65536 texpoint # The TeX typesetting system uses
texsp texscaledpoint # this for all computations.
computerpoint 1|72 inch # The American point was rounded
point computerpoint
computerpica 12 computerpoint # to an even 1|72 inch by computer
postscriptpoint computerpoint # people at some point.
pspoint postscriptpoint
twip 1|20 point # TWentieth of an Imperial Point
Q 1|4 mm # Used in Japanese phototypesetting
# Q is for quarter
frenchprinterspoint olddidotpoint
didotpoint germandidotpoint # This seems to be the dominant value
europeanpoint didotpoint # for the point used in Europe
cicero 12 didotpoint
stick 2 inches
# Type sizes
excelsior 3 oldpoint
brilliant 3.5 oldpoint
diamondtype 4 oldpoint
pearl 5 oldpoint
agate 5.5 oldpoint # Originally agate type was 14 lines per
# inch, giving a value of 1|14 in.
ruby agate # British
nonpareil 6 oldpoint
mignonette 6.5 oldpoint
emerald mignonette # British
minion 7 oldpoint
brevier 8 oldpoint
bourgeois 9 oldpoint
longprimer 10 oldpoint
smallpica 11 oldpoint
pica 12 oldpoint
english 14 oldpoint
columbian 16 oldpoint
greatprimer 18 oldpoint
paragon 20 oldpoint
meridian 44 oldpoint
canon 48 oldpoint
# German type sizes
nonplusultra 2 didotpoint
brillant 3 didotpoint
diamant 4 didotpoint
perl 5 didotpoint
nonpareille 6 didotpoint
kolonel 7 didotpoint
petit 8 didotpoint
borgis 9 didotpoint
korpus 10 didotpoint
corpus korpus
garamond korpus
mittel 14 didotpoint
tertia 16 didotpoint
text 18 didotpoint
kleine_kanon 32 didotpoint
kanon 36 didotpoint
grobe_kanon 42 didotpoint
missal 48 didotpoint
kleine_sabon 72 didotpoint
grobe_sabon 84 didotpoint
--
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy