When you type a comment or a description (which is “comment 0”) for a bug in Bugzilla, certain phrases are treated as special.
For example, the word “bug” followed by a space and then a decimal number is converted into a link to another bug. Therefore, rather than saying
See also bugs 1234 and 2345.
you could instead say
See also bug 1234 and bug 2345.
and the links will be formed by “autolinkification”—you will only see the links after you click the [commit] button.
For more information, see the Bugzilla help topic.