My original thought was “post hoc” in a post hoc multiple comparison procedure means that the procedure is taken after an omnibus test (such as ANOVA F test) gives a significant result.
But after reading Howell's Statistical Methods for Psychology, “post hoc” in a post hoc multiple comparison procedure means the procedure is planned after data collection, and “prior” in a prior comparison means the procedure is planned before data collection.
So was my original thought wrong?
Is Tukey–Kramer method (Tukey's HSD) post hoc?
How about Scheffe method?
A table from Howell's book (here is link to Google Books, although not having the table):