Basically, all npcs are divided into groups in the Pedstats.dat file.
For example, Tad and Gord both use the "P_STRIKER_A" stats, "P" meaning preps and "STRIKER_A" referring to their spawn name. If you were to edit P_STRIKER_A both Tad's and Gord's stats will be changed.
Some npcs have their own stats, for example most bosses(J_TED, G_JOHNNY and GS_GARY), however both Darby and Bif use something else, I don't remember what though.
Those P_BOXING_NAME ones you found are used in the boxing mini-game.
Read up more about pedstats modifying here:
http://www.bully-board.com/index.php?topic=14626.0Here are some groups:
J_DAMON: Damon
J_STRIKER_A: Kirby and Dan
J_MELEE: Bo and Casey
J_GRAPPLER_A and B: Yuri and that other wrestling guy. I don't remember who uses which though.
G_STRIKER_A: Peanut, Ricky and Lucky (Also used by Zeke, Lightning uses P_STRIKER_A)
G_MELEE: Vance and Lefty
G_GRAPPLER: Hal and Norton
G_RANGED_A: Unused
P_STRIKER_B: Justin and Parker
P_GRAPPLER: Bryce and Chad
N_STRIKER_A: Fatty and Melvin. B is used by Algernon.
N_RANGED and N_MELEE: I don't remember which one is used by whom, but Bucky, Donald, Cornelius and Thad
GS_MALE: All of the male non cliques, except for little kids and Constantinos
GS_FEMALE: All female non cliques, except for little kids
GS_MALE_TATTLER: Constantinos
GS_FEMALE SMKID AND GS_MALE SMKID: Little kids, meaning Gloria, Melody, Karen, Sheldon and that other guy.
PF_BASIC_A: All prefects but Seth
PF_BASIC_S: Seth
PF_OFFICER_A: Cops
PF_ORDERLY: Mental Asylum guards
CV_MALE, CV_FEMALE, CV_MALE_OLD and CV_FEMALE_OLD: Adults