Test names

In t/README it is written:

The test files are named as:

        tNNNN-commandname-details.sh

where N is a decimal digit.

First digit tells the family:

        0 - the absolute basics and global stuff
[...]
        7 - the porcelainish commands concerning the working tree

There are now some test which have 8 or 9 as first digit (e.g.
t8002-blame.sh, t9001-send-email.sh). What is the family for them?
What number for example gitweb test should have?

Second digit tells the particular command we are testing.

Is there any naming rule, or just increment it by one when adding new test
in the same family?

Third digit (optionally) tells the particular switch or group of switches
 we are testing.

What tells the fourth digit?
-- 
Jakub Narebski
Warsaw, Poland
ShadeHawk on #git