B5c.No offensive player may have a position at the snap, either from his initial set or as the result of a shift, that places him between the C and QB. The snap must not pass "through" any player.
Whiff – PLYCHK has no check to determine if a player is between the C and QB.

C2.No play may be designed such that the reception of the "handoff/pitch to" is recorded as a forward pass. The play-by-play log must record all such transfers of the ball with the phrase "gives to" when practiced in the play editor without a defense present.
Whiff – there is no way to determine if this rule is violated without actually testing the play in the editor. One RB may be too fast and it’s a violation… another may time it right and it’s a handoff.

D2a.The marked end spot for any "timed pass" may not exceed 15 yards from the LOS. Furthermore, the logic boxes and movement paths for the intended receiver may not exceed that same 15 yard limit.
Half-Whiff – while PLYCHK can correctly discern that the timed pass is not thrown beyond the 15 yard limit, there is no way to determine if the intended receiver violates the limit. Unlike a check pass, the "intended receiver" is unknown unless the play is run in practice.

D3a. When "inside the box," no player who's logic includes "pass-check receivers" or "timed pass" may have a logic box or movement path that touches or extends beyond the LOS.
D3b. When "outside the box," no player who's logic includes "pass-check receivers" or "timed pass" may have a logic box or movement path that touches or extends beyond the 15 yardline in the Play Editor, 5 yards behind the LOS.
Half-Whiff – while PLYCHK can correctly report that a logic box is within the illegal "seperator zone", it does not flag a violation if movement path breaks this rule.

D3c.A passer may never have any logic which includes any of the "run" (inside, left, to daylight, etc.) logic choices.
Choke – PLYCHK does not discern between QB and any other position. With the check on (which it is in the FBPro Federation CFG file) any player with run logic will get flagged. It is only a violation if the QB has the run logic… it is perfectly legal for RB, WR, or TE.

D6.On all passing plays, at least 2 eligible receivers other than the passer must have "look for pass" logic that is not followed by any blocking logic.
D7.In every passing play that is a "check" pass, every player selected in the QB's "Pass - check receivers" logic must have "look for pass" somewhere in his own logic.
Choke – this is the most common PLYCHK gaff. The rules state that at least two players must have LFP, and that all players checked by the QB must have LFP. PLYCHK somehow combines the two and flags a violation if two receivers are not checked by the QB. It is perfectly legal to check only one receiver, as long as a second (unchecked) receiver also has LFP logic with no blocking commands. This is extremely common on 1-check screen passes.

E1.All defensive plays must use a total of at least five (5) DL/LB, of which at least three (3) must be defensive linemen (DE/DT) and at least one (1) must be a linebacker (LB). In all cases, regardless of DL/LB allotment, no more than six (6) defensive backs (CB/S) may be included in a play.
Half-Whiff – there is a check in PLYCHK for the required 3 DL and 1 LB, but the "combined" check is for only 4 players… there is unfortunately no choice for 5 (or, similarly, a max 6 DB).

E4.All defensive plays must include at least 2 DL that use actual DL logic… that is, the choices offered for defensive linemen when you attempt to add logic for them in the play editor, such as "Pass Rush", "Run Rush - ???", or "Read". Other DL may be dropped into zones using the VPNFL "zone-blitz" techniques, but only after at least 2 players are programmed to use true DL logic.
Whiff – again, PLYCHK contains no check at all for this rule and the logic it requires.

Section F – SPECIAL TEAMS RULES
Whiff – PLYCHK does not make any checks of special teams plays.