All.inv files growing

[Peter Grass]

I use FP2000 in XP Pro operating system to develop and
maintain several sites. Files named _vti_txt/All.inv are
growing megabytes large, 10mb, 15mb even.

What are these All.inv files & are they needed? Is it safe
to delete uncessary All.inv files and how can I delete
those unecessary files?

Thank you,
Peter