I would use the ASLA Evidence Guides for Teacher Librarians as a benchmark for TL achievement. They provide a non-exhaustive list of practical ways to meet each of the AITSL Teacher Standards through a TL position. I use the documents to inform my practice with the examples provided for whichever standard I am trying to address. They are also useful as a basis to further explore the role – again through reviewing the examples provided. Comparing the proficient document to the highly-accomplished document could provide ideas about how I might need to lift my gain to achieve that level.