Message Text Numbers
 

Here is a fairly complete list of Message Text Numbers:

#define MT_Say 256
#define MT_Tell 257
#define MT_Group 258
#define MT_Guild 259
#define MT_OOC 260
#define MT_Auction 261
#define MT_Shout 262
#define MT_Emote 263
#define MT_Spells 264
#define MT_YouHitOther 265
#define MT_OtherHitsYou 266
#define MT_YouMissOther 267
#define MT_OtherMissesYou 268
#define MT_Broadcasts 269
#define MT_Skills 270
#define MT_Disciplines 271
#define MT_Unused1 272
#define MT_DefaultText 273
#define MT_Unused2 274
#define MT_MerchantOffer 275
#define MT_MerchantBuySell 276
#define MT_YourDeath 277
#define MT_OtherDeath 278
#define MT_OtherHits 279
#define MT_OtherMisses 280
#define MT_Who 281
#define MT_YellForHelp 282
#define MT_NonMelee 283
#define MT_WornOff 284
#define MT_MoneySplit 285
#define MT_LootMessages 286
#define MT_DiceRoll 287
#define MT_OtherSpells 288
#define MT_Fizzles 289
#define MT_Chat 290
#define MT_Channel1 291
#define MT_Channel2 292
#define MT_Channel3 293
#define MT_Channel4 294
#define MT_Channel5 295
#define MT_Channel6 296
#define MT_Channel7 297
#define MT_Channel8 298
#define MT_Channel9 299
#define MT_Channel10 300
#define MT_Crits 301
#define MT_SpellCrits 302
#define MT_TooFarAway 303
#define MT_Rampage 304
#define MT_Flurry 305
#define MT_Enrage 306
#define MT_SayEcho 307
#define MT_TellEcho 308
#define MT_GroupEcho 309
#define MT_GuildEcho 310
#define MT_OOCEcho 311
#define MT_AuctionEcho 312
#define MT_ShoutECho 313
#define MT_EmoteEcho 314
#define MT_Chat1Echo 315
#define MT_Chat2Echo 316
#define MT_Chat3Echo 317
#define MT_Chat4Echo 318
#define MT_Chat5Echo 319
#define MT_Chat6Echo 320
#define MT_Chat7Echo 321
#define MT_Chat8Echo 322
#define MT_Chat9Echo 323
#define MT_Chat10Echo 324
#define MT_Chat1Echo 315
#define MT_Unused3 316
#define MT_ItemTags 317
#define MT_RaidSay 318