There's a difference between the WPA rules for 10-ball, and WPA+ rules for 10-ball. The difference being this (these are the WPA+ rules, the part I'm referring to is bolded below):
Call Shot:
Players have the option of either calling their shot or calling a safety. Aside from obvious shots, the shooter must specify which ball and which pocket is being called. If a player is shooting a bank, combination or any kind of ambiguous shot, the player must call the shot.
If a player calls a shot and misses, the incoming player will have the option to shoot or make his opponent shoot again. No matter how many times a player misses a called shot, failure to pocket that ball legally or wrongfully pocketing the ball in another pocket allows the opposing player the option to shoot or make his opponent shoot again.
In WPA rules, if a player misses a called shot, as long as no ball is pocketed (either the object ball in the wrong pocket, or another incidental ball on the table), the incoming player *HAS* to accept the table as-is.
I guess the WPA rules are what folks responding to this thread are referring to when they say "call pocket, not call shot". When people say "call shot," I think of bar rules where you are forced to call every contact that the cue ball and object ball makes as the object ball goes to the pocket (in other words, everything in the "shot"). Not what's intended terminology-wise.
-Sean