$ zgrep -A5 458-2 /usr/share/doc/less/changelog.Debian.gz
less (458-2) unstable; urgency=low
* Merge 458-1ubuntu1
- debian/lesspipe{.1}: Make lesspipe treat ddebs the same as it does debs
and udebs (LP: #1180013).
What are ddebs?
I think it is not a typo as debs and udebs are explicitly listed.