Is this really how it is?

[Jones]

Or even cheaper, get an ordinary ruler. Lay it against the chain, and measure the chain along that length. A new chain should have the pins centered on the 1" and the 12" mark. When that measurement stretches to 12 1/8" or longer, it's high time for a new chain.

Great information. Is this true for all chains? Mountain and road? I always wondered how to tell if your chain was worn. Thanks.
Jones