The following conventions are used for names of macros, strings, and
registers.
External names available to documents that use the
groff ms
macros contain only uppercase letters and digits.
The package reserves the following identifiers for internal use.
*,
@,
and :;
and
When selecting a name for your document’s own macros,
strings,
and
registers,
avoid those reserved by
groff ms
and those defined by
GNU
troff see
Macro Index,
String Index,
and
Register Index,
or
groff_char(7)
for complete lists thereof.
groff ms
organizes most of its internal names into modules.
The naming convenion is as follows.
*name.
@name.
:name;
these are used only within the
par
module.
!index.