According to the PDF Association Syntax Guide Page 26 (https://pdfa.org/wp-content/uploads/2019/06/TaggedPDFBestPracticeGuideSyntax.pdf#page=26), and <Lbl> tag should be applied to any labelling text, even if it is inside a caption for a figure or table. However, every time I run the accessibility check in Acrobat Pro on this, it fails it; it appears the check thinks that only LItems should contain an <Lbl> as a child.

Additionally, I think <Lbl>s should be allowed as the children of Paragraph tags as well, in the case where a single paragraph is labelled but the labelling text is not indicating the start of a new section. (The next paragraph belongs to the preceding header.)