Requirements
Based on initial examination of section topics, some sections should not have topics generated and store in the section topics pipeline:

• (M) References
• (M) External links
• (M) Further reading
• (XS) last section - Update: this rule is too strong. it actually wipes out plenty of potentially useful sections, see /user/mfossati/section_topics/last_section_titles on HDFS for a detailed dataset
• We can base which sections to exclude similar to the task for add links T279519

Excluded:

• (XL) tree type sections (if possible?)
• (S) Infoboxes - can be used to understand what are important sections on the article level
• (L) Sections without textual content

Should we exclude templates?

Usage Note:
Note that section topics will be used for section level image suggestions and certain sections are to be excluded to have images suggestion to them as per https://phabricator.wikimedia.org/T311730. The sections excluded from having topics is a subset of section excluded of having images recommended.

Estimated complexity breakdown

Complexity varies depending on what we want to exclude:

• sections without textual content may be tricky. L complexity to figure that out
• references, external links, further reading can be tackled with section alignments machine-learned by Research. M complexity
• infoboxes should be easy - S
• last section with category links is trivial - XS
• tree-type sections look like the upper bound, as I have no idea - XL