🚀 go-pugleaf

Reference page space would work great for vertically centering if your
text box was always the same size and there was always one line of text.

But if the text box varies in depth and there may be a different number
of lines of text, the only way I know to automatically vertically center 
is to put the text inside a one-cell table. Spacing in a one-cell table 
is very controllable: cell margins via the table style and the paragraph 
style, and vertical centering via the paragraph style. You can even 
build the rule into the table style. Converting a single short paragraph 
of text into boxed text as an anchored table is as easy as highlighting 
the paragraph and choosing Table > Convert to Table and choosing a table 
style. FM even remembers which table style you chose, so you don't have 
to specify the table style after the first time.

Why is it you can't use a table? I've done books with hundreds of short 
boxed items, some anchored in text (each one as a table) and some locked 
to the page (each one as a table in a text box in a graphic frame).

-- 
Kenneth Benson
Pegasus Type, Inc.
www.pegtype.com