Simple List
The PDF specification defines list structure in section 14.8.4.3.3 (List Elements). The structure types for lists in PDF documents are:
L - the List tag, which contains one or more LI tags.
LI - the List Item tag. List item tags can contain Lbl and LBody tags.
Lbl - the list item label. Contains distinguishing information such as an item number or bullet character.
LBody - the list item body. Contains list item content, or in the case of a nested list, it may contain additional List tag trees
In PREP, you can easily tag a list automatically by using the List Split feature.
In case, it doesn't work properly for some lists, you can follow the manual approach here too. Also, Please do share the feedback when you encounter such cases.
Step 1 : Split the list into smaller parts
Step 2 : After splitting, changing type of bullets/number as Lbl and list item content as Lbody
Step 3 : Group them together into individual list items and individual list items into a List tag
You can also follow the detailed video here :
Nested List
In case of Nested list, the entire List tag of the child-list needs to be tagged with the Lbody tag of the parent list.