Why no official documentation about how to unlock Job?

[Ruanark]

For the minimum lvl you need to lvl cross classes in order to obtain all available cross class skills, here's a list:

THM: 26 (SMN, SCH, WHM)
ACN: 34 (BLM, SCH, WHM)
CNJ: 34 (SCH, PLD, SMN*)
GLA: 34 (WAR)
MRD: 26 (PLD, DRG, MNK)
LNC: 34 (MNK, BRD)
PUG: 42 (WAR, DRG, BRD)
ARC: 34 (BLM, ACN*)

So, a BLM needs lv34 ACN and 34 ARC to have all cross class skills,
WHM needs 26 THM, 34 ACN
SMN needs 34 CNJ(or 34 ARC*), 26 THM
SCH needs 34 CNJ, 26 THM
PLD needs 34 CNJ, 26 MRD
WAR needs 34 GLA, 42 PUG
DRG needs 26 MRD, 42 PUG
MNK needs 34 LNC, 26 MRD
BRD needs 34 LNC, 42 PUG

*Appears some sites SMN as being THM/CNJ and others list it as being THM/ARC, we'll find out soon which is correct