I disagree with one point in this interesting and thoughtful post.
2) The global option "nospaces", according to the manpage, is described
as:
Ignore leading and trailing spaces in data items (GNU tbl only).
The following point may be a question of correct interpretation of this
statement. Does the underbar "_" qualify as a data item in this
terminology? I positively think so, because the manpage states
If a data line consists of only ‘_’ or ‘=’, a single or double
line, respectively, is drawn across the table at that point;
The post goes on to suggest that under option "nospaces" a data line
consisting of an underbar followed by a space should be interpreted
as if it had been a bare underbar, signifying a line across the whole
table.
I agree that an underbar followed by a space qualifies as a data item.
However, the man page clearly distinguishes between "data item" and
"data line". Ignoring spaces in a data item does not destroy its
itemhood. It does not magically become a data line.
Doug