This thread is intended to curate a list of keywords we want to reserve in the 2018 epoch. Feel free to propose the inclusion of keywords you think we need (and for what it is needed). This is not necessarily the list we will reserve.
Keywords we (might) want to reserve
For general effect polymorphism
The inversion of
The panic effect and its inversion
The partiality effect and its inversion
EXPR is PAT expressions
For trait objects and VLAs.