This is a section of the rules that seems to cause confusion every year.  It refers to special AB limitations on players with low at-bats vs. one type of pitching:
 
10. Any played allowed 150 or more at-bats who had less than 50 at bats against a pitcher who throws from a particular side and whose batting average is at least 40 points higher against those pitchers are limited to 50 at-bats against those pitchers.  Players with less that 25 at bats against a certain type of pitcher are similarly be limited to actual at bats.

 

The following special AB limits apply based on players having >= 150 ABs, but having > 50 ABs against one side pitching (all vs LHP) with their Avg being >= .040 higher against that side (vs LHP):

 

Dobbs Greg 50 vs L 
Barton Daric 50 vs L 
Reed Jeremy 50 vs L 
Vizquel Omar 50 vs L 
Vazquez Ramon 50 vs L 
Blum Geoff 50 vs L 


 

The following special AB limits apply based on having <= 25 ABs against one side of pitching with their Avg being >= .040 higher against that side indicated:

 

Everidge Tommy 24 vs L 
Hernandez Luis 24 vs L 
Gamel Mat 23 vs L 
Young Eric 23 vs L 
Fiorentino Jeffrey 22 vs L 
Delgado Carlos 18 vs L 
German Esteban 18 vs L 
Morales Jose 17 vs L 
Patterson Eric 16 vs L 
Shelton Chris 16 vs L 
Wise DeWayne 15 vs L 
Norton Greg 14 vs L 
Towles J.R. 14 vs L 
Toregas Wyatt 12 vs L 
Avila Alex 10 vs L 
Bixler Brian 10 vs L 
Cash Kevin 7 vs L 
Nady Xavier 6 vs L 
Burke Jamie 5 vs L 
Joyce Matt 4 vs L 
Owens Jerry 2 vs L 
Quiroz Guillermo 1 vs L 
Jones Brandon 1 vs L 
Murton Matt 22 vs R 
Perez Fernando 21 vs R 
Rodriguez Sean 14 vs R 
Barrett Michael 13 vs R 
Dillon Joe 11 vs R 
Riggans Shaun 11 vs R 
Carlin Luke 8 vs R