Is your feature request related to a problem? Please describe it.

apacite uses \cite and \citeA for parenthesis and in-text citation, and <> and [] for prenotes and postnotes. The prenotes syntax breaks the suggestion list / completion that normally shows all available references when typing \cite<prenote>{author...}.

Describe the solution you'd like

It would be great if the <> prenotes were supported and worked similarly to the more standard \cite[prenotes]{author...} format, which does give completion suggestions on available author...s.

Describe alternatives you've considered

For the syntax highlighting to work, I added

syntax match texCmdRef nextgroup=texRefOpt,texRefArg skipwhite skipnl "\\[Ee]dcite[pt]\?\>\*\?"
syntax match texCmdRef nextgroup=texRefOpt,texRefArg skipwhite skipnl "\\[Tt]ranscite[pt]\?\>\*\?"
syntax match texCmdRef nextgroup=texRefOpt,texRefArg skipwhite skipnl "\\citeA[pt]\?\>\*\?"

So the highlighting is correct in the tex source files, but completion is missing.