Tags most used are:
Paragraph (P)
Blocks / units of text are considered paragraphs.
Heading Level 1-6 (H1-H6)
Headings for parts of the document and can be nested. The top-most heading is level 1, with levels 2 to 6 beneath them if required
Image/Figure (Image)
Images, diagrams and illustrations are tagged as "Image". Any figure tag should have an alternative text describing the figure's contents.
Link (Link)
A link tag marks a link, for example to an external web page. The address-attribute contains the URL of the referenced site.
Table (Tbl,TR,TH,TD)
Tabular content needs to tagged as a table. The header cells(TH) need to grouped separately from data cells(TD) into separate rows(TR) and all combined together in a Table Group.
List (List, LI,Lbl,Lbody)
List content needs to be tagged as a list. Each bullet or numbered element need to be tagged as Lbl and each list content needs to be tagged as Lbody
Artifact (ignored by screen readers)
Elements that do not contribute to a document's contents are tagged as "Not relevant (ignored by screen readers)". In Prep, any untagged items automatically gets tagged as artifacts. You can delete any detected tag to make it an artifact. Screenreaders ignore such elements.