As per : https://review.whamcloud.com/c/fs/lustre-release/+/64508/comment/d91db050_4434df8d/

Improve the lustreapi(7) man page by organizing the flat list of functions into subsections (.SS).

Requirements:

• Group by Area: Changelogs, FID Handling, File Layouts, HSM, Nodemaps, Tunables, PCC, and Quotas, Miscellaneous