If a port have dozen of flavors, using additional helpers allow to dramatically desrease size of Makefile
PLIST is always handled by helper, wonder why PLIST_FILES was missed.
Override COMMENT is useful for flavored plugins, CONFIGURE_[ARGS|ENV] is also useful as helper — it allow to avoid extra .ifdef in Makefile
For example, with additional helpers I can simply use
filter-clamav_COMMENT= Check messages with ClamAV in OpenSMTPD filter-clamav_RUN_DEPENDS= clamscan:security/clamav filter-clamav_PLIST_FILES= libexec/opensmtpd/filter-clamav \ man/man8/filter-clamav.8.gz filter-clamav_CONFIGURE_ARGS= --with-experimental-filter-clamav
instead of two blocks
filter-clamav_RUN_DEPENDS= clamscan:security/clamav
and
.if ${FLAVOR:M*clamav} COMMENT= Check messages with ClamAV in OpenSMTPD PLIST_FILES= libexec/opensmtpd/filter-clamav \ man/man8/filter-clamav.8.gz CONFIGURE_ARGS= --with-experimental-filter-clamav .endif