You signed up for CathInfo 11 years ago, and you still don't know the basics of how to assist at a Tridentine Mass?

Really?

And if you "follow the others" on Sunday, wouldn't you be familiar with the Mass by now? It's not rocket science. There's also the hand missal.
Our small mission chapel has nice Angelus Press softcover missalettes in every pew.

Also, why post this in the Library? That subforum is for docuмents/books and NO DISCUSSION WHATSOEVER. That is clearly stated in the subforum description.

Some are thinking your account was hacked, Cato. Someone actually reported your post to the Moderator. Please explain yourself.

Regarding the postures at Mass, however, there are no OFFICIAL postures as you ask for. You are talking about rubrics.

Rubrics comes from the Latin for RED.

Rubrics are literally the words IN RED INK in the Missale Romanum -- used by the priest. The red text always describes what the priest should be doing at this or that point. Think of it like the "narrator" in a story. The words in black are what he *says*. Like the dialog in a story.

As for the Faithful, it's Tradition and local custom. There are no papal bulls, catechisms, or rubrics (strictly speaking -- see my definition above) for them.

So aside from following the various hand-missals and "do what the others do", there is no answer or source you can be pointed to.

Liturgists deal with the Liturgy and those who are in it (clerics). Liturgists don't dictate much for the laity. And for good reason. In some countries, there are no pews or even chairs. The ubiquitous kneelers seen in countless Catholic chapels? Didn't exist before the 20th century. Catholics used to kneel on the ground. Talk about us getting soft in the modern age! So yeah, it's just custom.

Except if you don't kneel for the Consecration, there would be something wrong.