which unix-pc files MUST be writeable by others?

[daniel.r.levy]

Can someone tell me which unix-pc files, under version 3.51 system software,
MUST be writeable by others?  I checked my system (that's my personal system,
at home) and I found a surprising number of files and directories to be
writeable by anybody, including some humdingers like /, /usr, /usr/bin, and
/usr/lib/ua.  Now some of this stuff seems to be connected with preference
parameters (like /usr/lib/ua/.blanktime) that need to be alterable from any
user's office, and others obviously SHOULD be writeable by others (/tmp,
/usr/tmp, /usr/lib/spell/spellhist), but things like / shouldn't be.

Tnx...
-- 
Dan'l Levy                 UNIX(R) mail:  att!ttbcad!levy, att!cbnewsc!danl
AT&T Bell Laboratories
5555 West Touhy Avenue     Any opinions expressed in the message above are
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