.vs [space] ¶.vs +space ¶.vs -space ¶\n[.v] ¶Change (increase, decrease) the vertical spacing by space. The
default scaling unit is ‘p’. If vs is called without an
argument, the vertical spacing is reset to the previous value before the
last call to vs.
GNU gtroff emits a warning in category ‘range’ if
space is negative; the vertical spacing is then set to the
smallest possible positive value, the vertical motion quantum (as found
in the .V register).
‘.vs 0’ isn’t saved in a diversion since it doesn’t result in a vertical motion. You must explicitly issue this request before calling the diversion.
The read-only register .v contains the vertical spacing; it is
associated with the environment (see Environments).
When a break occurs, GNU troff performs the following procedure.
\x escape sequence arguments
in the pending output line.
\x escape sequence arguments
in the line that has just been output.
Prefer vs or pvs over ls to produce double-spaced
documents. vs and pvs have finer granularity than
ls; moreover, some preprocessors assume single spacing.
See Manipulating Spacing, regarding the \x escape sequence and
the ls request.
.pvs [space] ¶.pvs +space ¶.pvs -space ¶\n[.pvs] ¶Change (increase, decrease) the post-vertical spacing by space.
The default scaling unit is ‘p’. If pvs is called without
an argument, the post-vertical spacing is reset to the previous value
before the last call to pvs. GNU troff emits a warning in
category ‘range’ if space is negative; the post-vertical
spacing is then set to zero.
The read-only register .pvs contains the post-vertical spacing;
it is associated with the environment (see Environments).