[Info-vax] improve performance of /EXCLUDE

[Bob Koehler]

In article <d29c0792-a507-49c5-b245-35e61860343b at googlegroups.com>, mcleanjoh at gmail.com writes:
> 
> I can see that being useful for some things (e.g. searching on a set of 
specific files) but not so much for wider use where the cost-benefit doesn't 
weigh up.

And a security hole for other things.  There may be data in some files
that ust be excluded from pre-indexing.