Your patch triggered something.  The keyword 'special' for the parameter
flag 't' is defined as "for special parameters defined by the shell".
Should it
also include user-defined parameters? Case in point, parameters used by
ztie to "tie" to a gdbm file. Technically, the parameter itself is defined
by the
user, yet it has the 'special' keyword.  Sorry if this seems to be
nitpicking,
but 57 years of computer logic it's hard to break the habit.

Also when I first started using ztie I expected the parameter to include the
key word 'tied'. Had to train myself to check parameter zgdbm_tied.

Thanks,

Jim