Innate level

The innate level of a spell is what is considered its spell level for the purposes of feats such as craft wand and brew potion. This is especially important where different casting classes receive the same spell at different spell levels.

It also is the level that monster special abilities use, such as spells known by a Balor or a Dragon, who do not have any classes in a normal spellcasting class.

Gameplay Notes

Apparently, True Seeing can be applied to wands despite having an Innate level of 4.

The reason for such is uncertain, as other spells that get reduced by domains in spell level cannot be wanded.