Before you get to Battalion you must go through R.anger I.ndoctrination P.rogram that basically weeds out the weak. When you get to Bat you go through OJT learning all the skills you need to accomplish the mission. After time usually no less than 6 months and depending on who is ahead of you, you go to Pre-Ranger where they teach the skills needed to get through Ranger School. Goto Ranger School. Pass. Go back to Battalion. Prepare and rehearse missions. that is life in the Battalion.
The general rule is E-4 and below are untabbed, until you goto ranger school. Can't get make Sergeant as 11B (Infantry) without Tab.
There are soft skills (supply, cook, clerk, mechanic, NBC NCO) that don't "have" to have their Tabs for promotion but they are generally looked down upon and end up going because that is what you do when you are in Battalion.
Hope that answers your questions, it may have changed a little since I was in.
Battalion born,
Battalion bred,
When I die,
I'll be battalion dead.
Cco 1/75 92-96