You may be right... there is a different manual for "Complete Chronicles" than for "Ages Beyond Myst". In Complete Chronicles it's on page 18 in the Frequently Asked Questions page.
In "Ages Beyond Myst" they elude to the use of Journey Cloths as saving where you'll return, but it obviously caused confusion so they added the FAQ in the latter version to make it clearer.
Here's what the Ages Beyond Myst manual says on page 17:
In some Uru Ages, you will find a number of Journey Cloths like this one. You’ll discover their primary purpose later, but they have
another handy function, as well.
The last Journey Cloth you touch in a particular Age becomes your return location to that Age.
From your Relto library shelf, select the Linking Book you wish to link with and touch the Journey bookmark that’s inside."
Anyway, it's a great game... if you don't have the expansion packs "To D'Ni" and "Path of the Shell", you should make sure you get them! They add a lot to the game.