If you have some additional information for a PR and for some reason do not want to (or cannot) edit the PR directly, you may append the information to the Audit-Trail field by mailing it to the PR submission address.
In order for GNATS to be able to recognize the mail as pertaining to an existing PR (as opposed to a new PR, see Submitting via e-mail), the Subject mail header field must contain a reference to the PR. GNATS matches the Subject header against the regular expression
\<(PR[ \t#/]?|[-[:alnum:]+.]+/)[0-9]+
to determine whether such a reference is present. Any text may precede or follow the reference in the Subject header. If more than one reference is present, the first is used and the rest ignored.
A PR reference matching the regular expression above has two parts. The second is the PR number (one or more digits). The first is either the capital letters 'PR' optionally followed by a separator character (blank, tab, hash mark or forward slash) or the category name followed by a forward slash. Following are some examples which match the regular expression:
PR 123 PR4567 PR#890 gnats/4711
The PR number and the category (if present) are checked for existence, and if the outcome is positive, the mail is appended to the Audit-Trail field of the PR. Note that the PR need not belong to the category because PRs may move between categories.
Outgoing emails sent by GNATS itself may be configured to have a Subject header field that refers to the PR in question:
Subject: Re: PR category/gnats-id: original message subject
This makes it extremely easy to follow up on a PR by replying to such an
email, see The dbconfig file and the sample,
default dbconfig file installed by mkdb.