I am trying to use the T5 model for keyword extraction. I want to be able to pass to the model a paragraph and get the same paragraph back, but with the keyword/key phrase surrounded with a special symbol. Is there a special token that T5 understands that would suit this task, or am I better off delimiting the key phrase with normal characters (for example a group of curly braces)?
Ex.
“…words my favorite key phrase more words …” →   “…words my favorite <special_t5_token>key phrase<special_t5_token> more words…”
or
“…words my favorite key phrase more words …” →   “…words my favorite {{{key phrase}}} more words…”
If I should just use normal characters, what symbol should I use (ex. bracket, parenthesis, curly brace) and how many of these characters should I put on either side of the key phrase?