THPDFStandardStructureType Type

• sstDocument through sstPrivate are grouping types that organize children without visible content of their own
• sstH through sstTFoot are block-level types covering headings, paragraphs, lists, and tables
• sstSpan through sstAnnot are inline-level types for runs inside block elements
• sstRuby through sstWP cover East Asian ruby and warichu annotation sequences
• sstFigure, sstFormula, and sstForm are illustration-level types
• sstDocumentFragment through sstArtifact cover remaining fragment, aside, title, note, emphasis, and artifact roles

Note the lowercase l in sstLbl and sstLBody, matching the PDF role names Lbl and LBody

Every structure element either carries an /S value from this enum or a custom name mapped back to one of these names through a role map