Re: .SPACE in mom

[Douglas McIlroy]

> .SP (or the groff request .sp) adds the current linespace (\n[.v]) to
> the requested distance when | is used, for which compensation needs
> to be applied:

Wording like this somewhat obscures the point.

.sp |d, where d is some vertical distance, provides that much space
from the top of the page above any immediately following text. The
nominal height of such text is the line spacing, \n[.v].

The vertical position of the "current point" for a sequence of \D
drawing commands begins on the current baseline for text. The
following code places the current point on the midline of an 11''
sheet of paper with no compensation necessary.
        .vs 0
        .sp |5.5i
        .vs

Doug