i found out very interesting things...
in project headphones
rv pros use s3[tm1],s4[tm1] whatever...
what is this???i;ve never heard of it in dvds.
some kinda variation in s6????
new developed technology in rv???
please let me know???

TM stands for target movement, which is simply a housekeeping label for high level prompts. This is beyond the scope of the DVD's, but many pros here teach these tools in a 1x1 environment, both in person and online.

Is there an advantage using [tm1] instead of [1]? Because the brackets means target movement.

In this case the brackets mean "element", not any kind of movement. In any case, think of it this way:

A standard movement exercise - from the top of [1] SSBP - is a movement on one specific site template element.

What we would consider a "target movement" would be a prompt that pertains to the site as a whole, for example: the activity at the site SBP.

Then there's [SM1], or a site movement. This would be used for a prompt that would take us away from the original target site, eg: the origin of [1] SBP. Sure, you could use a header like S1 [1] / origin, or something like that, it's just easier to write S1 [SM1].

See what I'm sayin'?

A subsession would just be marked [1] whereas a target geometry or other higher level prompt would use other notation.