Take the 2-minute tour ×      Length needs backslash but counter
does not, why?  share|improve this question add comment  1
Answer  up vote 6 down vote accepted  Counter names are used for
many purposes and it's safer to just append the name to the or
c@ or p@ and to use it as the argument of \arabic, \Roman and so
on. When you say \newcounter{Count}, LaTeX does, among other
things  \expandafter\newcount\csname c@Count\endcsname  Moreover
this makes more complicated to do local assignments to counters,
that should never be done, because LaTeX counters should always
be modified globally; for local counters there are the "TeX"
counters that can be defined by \newcount; in general, however,
\count@, \@tempcnta and \@tempcntb provided to this purpose by
the LaTeX kernel suffice. See this discussion on TeX.sx to know
more about doing local and global assignments to the same
variable, which shows that my statement before is quite drastic,
but one should know what they are doing when "violating" rules.
For lengths