VIM: Extra Highlighting

augroup highlight_sentences_that_end_with_colon
    au!
    " SOURCE: https://stackoverflow.com/a/30552423/490748

    " Add highlights to commented text.
    au Syntax * syn match moreTodo /\v([[:space:]]|^)@<=([[:alnum:].][^\]})])@=([[:space:]]=[^[:space:]]+)+(:)@<=([[:space:]]|$)@=/ contained containedin=.*Comment.*

    " Add highlights to non-commented text.
    au Syntax text,vimwiki syn match moreTodo /\v([[:space:]]|^)@<=([[:alnum:].][^\]})])@=([[:space:]]=[^[:space:]]+)+(:)@<=([[:space:]]|$)@=/

    hi def link moreTodo Todo
    " hi def link moreTodo Title
    " hi def link moreTodo Question
    " hi def link moreTodo Statement
augroup END

" There are subtle differences between these two statements.
"
" The first statement highlights matches in commented text. The beginning of the
" statement, "au Syntax *", allows it to highlight in all filetypes. However the
" ending of the statement, "contained containedin=.*Comment.*", constrains it to
" filetypes with highlight groups named "Comment", or contains the word "Comment",
" i.e. program-language filetypes that Vim knows how to highlight.
"
" The second statement highlights matches in non-commented text. The beginning of
" the statement, "au Syntax text,vimwiki", constrains it to text and vimwiki files.