<MTIfNonZero tag="MTEntryCommentCount">
<ol>
<MTComments>
<li><MTCommentAuthorIdentity> wrote something.</li>
</MTComments>
</ol>
</MTIfNonZero>
MTIfNonZero tag is currently not listed in the Movable Type template tag documentation but should be and it works.MTIfNonZero: Undocumented Movable Type template tag
Movable Type 3.0 introduced the MTIfNonZero template tag. If you would like to take action in your template only if a tag has a non-zero entry, use MTIfNonZero for valid XHTML.
Example:

1 comment
Commentary on "MTIfNonZero: Undocumented Movable Type template tag":
Pete o' Fun on wrote: #
It’s been staring me in the face for so long, and I never noticed! It’s used by default in the trackback section, but no in the comments! Thanks for verifying.