A helpful reference for me (and anyone else, too):
"Graphemes or sequences of them are sometimes placed between angle brackets, as in ⟨b⟩ or ⟨back⟩. This distinguishes them from phonemic transcription, which is placed between slashes (/b/, /bæk/), and from phonetic transcription, which is placed between square brackets ([b], [bæk])."
Also, this is helpful too:
Phonemic vs phonetic transcription for writing pronunciation.