> * Where is this tbl dependency on ms variables documented? > I did not find anything in man tbl. > * Are there another dependencies on another variables?
It has nothing to do with tbl. It's a feature of ms, which resets font size, vertical spacing, etc. to the values given by those number registers, at every paragraph. TS calls LP, which (in groff's version of ms) eventually calls par@reset, as far as I can tell. You may want to look at the original ms manual by M. E. Lesk, groff's documentation (info groff), and perhaps read the code of groff's s.tmac.
