# What callbacks i must to register,to catch start and end of paragraf and any other structures in lualatex

Help me please,what callbacks i must register to catch starting and ending of structures in lualatex such as paragrafs,lists,items of lists,tables,sections,subsections,sub...subsections,ETC. How i can learn,what the structure start or end in this moment and get and change content of this structure,if it need. Thanks everybody for the help.

• Most callbacks operate on full paragraphs. You have to be more specific about what you want to do to the paragraph. – Henri Menke Mar 10 at 18:14
• If you are inspecting the shipout box, paragraphs are contained in local_par sublists. – Henri Menke Mar 10 at 18:15
• If you mean LaTeX structures like \begin{section} or \begin{itemize}, then unfortunately LuaTeX has no native understanding of these structures, as all of LaTeX is implemented in TeX macros and as far as TeX/LuaTeX is considered, all of these are just \defs that expand to some stream of tokens or another. – ShreevatsaR Mar 10 at 18:34