Does not work the escape character "\" in title

Do not work the following structure in front matter:

title: \[Travel notes.\]
title: \"Travel notes.\"
title: Travel notes\: first

Is it possible to use in title “”, [], : ?

It’s just YAML. You should quote all strings that are not simple, alpha-numeric values. You can use double quotes if you want to use escape sequences or use single quotes for literal strings:

title: "[Travel notes.]"
title: "\"Travel notes.\""
title: "Travel notes: first"

title: '[Travel notes.]'
title: '"Travel notes."'
title: 'Travel notes: first'

Thanks a lot for your help.