Ignore .ns (no-space mode), .ps (change point size), .ta (tab control)

for now.  All of these just cause a bit too much or too little
whitespace, but no serious formatting problems.
Triggered by reports from brad@.

1 files changed, 14 insertions, 0 deletions

diff --git a/roff.7 b/roff.7
index 2b323442..0cea7f84 100644
--- a/roff.7
+++ b/roff.7
@@ -537,6 +537,16 @@ section with the
 .Cm \&Sh
 macro will reset this register.
 .El
+.Ss \&ns
+Turn on no-space mode.
+This line-scoped request is intended to take no arguments.
+Currently, it is ignored including its arguments,
+and the number of arguments is not checked.
+.Ss \&ps
+Change point size.
+This line-scoped request is intended to take one numerical argument.
+Currently, it is ignored including its arguments,
+and the number of arguments is not checked.
 .Ss \&so
 Include a source file.
 Its syntax is as follows:
@@ -554,6 +564,10 @@ only accepts relative paths not containing the strings
 .Qq ../
 and
 .Qq /.. .
+.Ss \&ta
+Set tab stops.
+This line-scoped request can take an arbitrary number of arguments.
+Currently, it is ignored including its arguments.
 .Ss \&tr
 Output character translation.
 This request is intended to have one argument,