The AM26LV31E datasheet, a differential line driver, states this (on page 4):
and this (on page 10):
At best, this seems ambiguous and, at worst, contradictory. Is the logic of this statement (8.1) clear to any of you?
The logic is clear, though it may be confusing to a user of the chip.
Let's put it this way. The wording of section 8.1 is from the viewpoint of the designer of the chip. It says that "the maximum tolerable current must be ±30mA or greater" -- in other words if the chip can tolerate exactly ±30mA, then mission accomplished. If it can accomplish more than that, well that's cool too.
Table 6.3 is from the viewpoint of the user of the chip. If you have a chip whose maximum tolerable current is guaranteed to be ±30mA, but in practice it could be even higher than that, then what's your recommended operating current? Well, to be safe you'd better make sure it never exceeds that ±30mA.
In the end it's just a bit of semantics.