For instructions on how to use software it's often useful to include key references. This is already possible using the < key > tag, but for many keys, it's slow to write, and not very readable.
Boostnote had in the initial app a shortcut [[key]] (two square brackets). Could somethinglike this be added as a feature ?
It's fast to write, and easy to ready. Plus it does not seem to interfere with other tag combos.