Use keycode for Print Screen(`KC_PSCREEN` or `KC_PSCR`) instead of `KC_SYSREQ`. Key combination of 'Alt + Print Screen' is recognized as 'System request'.
Solves my personal 'the' problem. I often got 'the' or 'THe' wrongly instead of 'The'. Oneshot Shift mitgates this for me.
https://github.com/tmk/tmk_keyboard/issues/67
## Modifier/Layer stuck
Modifier keys or layers can be stuck unless layer switching is configured properly.
For Modifier keys and layer actions you have to place `KC_TRANS` on same position of destination layer to unregister the modifier key or return to previous layer on release event.
This feature is for *mechanical lock switch* like this Alps one.
http://deskthority.net/wiki/Alps_SKCL_Lock
Using enabling this feature and using keycodes `LCAP`, `LNUM` or `LSCR` in keymap you can use physical locking CapsLock, NumLock or ScrollLock keys as you expected.
Old vintage mechanical keyboards occasionally have lock switches but modern ones don't have. ***You don't need this feature in most case and just use keycodes `CAPS`, `NLCK` and `SLCK`.***