[Mike Fieschko]

If it were a law, there wouldn't be any exceptions to it, would there?

Canon Law allows 'exceptions', sometimes called 'derogations'. When made/issued/permitted, they can be accomplished, for example, through indults.

For example, when we in the United States kneel at Mass from the 'ecce Agnus Dei' ('this is the Lamb of God'), it's because the US bishops requested and received an 'indult' from the posture prescribed in the General Instruction. Other countries don't kneel from that point on.

[sinkspur]

Other countries don't kneel from that point on.

My parish doesn't kneel from the Our Father to the distribution of the Eucharist. Quite European of us, isn't it?