Characters that form pairs. The % command jumps from one to the other. Only character pairs are allowed that are different, thus you cannot jump between two double quotes. The characters must be separated by a colon. The pairs must be separated by a comma. Example for including '<' and '>' (for HTML):

:set mps+=<:>

A more exotic example, to jump between the '=' and ';' in an assignment, useful for languages like C and Java:

:au FileType c,cpp,java set mps+==:;

For a more advanced way of using "%", see the matchit.vim plugin in the $VIMRUNTIME/pack/dist/opt/matchit directory. add-local-help

(default "(:),{:},[:]")