A run down of how the divisions are formed

Upon their arrival at Recruit Training Command Great Lakes, (RTC) new Seaman Recruits will go through a simple sort. Recruits who joined with a future Musician (MU) rate as well those with music, flag/drill, or ROTC experience are assigned to a 900 division if the need is there.

Those male recruits under a Spec Ops contract are assigned to a 800 division. Female recruits who join under Spec Ops contracts such as AIRR or EOD are added to regular divisions. There are usually only 25 or fewer 800 divisions a year, therefore every Pass In Review group will have one, but it is possible for a group to have more than one 800 division.

One to four divisions fill in a day. Those Seaman Recruits that will not be in an 800 or 900 division are assigned to divisions randomly upon their arrival at RTC. 

Having an all-female division is very rare. Females are almost always placed in what is called an integrated division, which simply means a division is made up of both males and females. Males are either assigned to an integrated division or one that is all male. 
At times a division can fill and there will still be Recruits waiting to be placed in a division. These Recruits are held and will be a part of the next division that is formed.

Other times there can be a division that still needs more recruits to be full. That division must wait until the next group of Recruits arrives to be filled. This group is called a Push Division. Recruits in a Push Division have to wait for more recruits to arrive to fill the division. Some of the Recruits in those divisions will be at the RTC for 7 1/2 weeks, 8 Fridays, rather than the norm of 8 1/2 weeks, 9 Fridays. At times there will be Recruits who will need to be held over to help fill later divisions. These recruits will spend 9 ½ weeks, 10 Fridays at RTC. This is more likely to happen when Recruits arrive in November and December due to the large number of Recruits that can ship early due to the Navy Recruiting Holiday Stand-down. It may also possible happen when there is a week without a PIR or if a storm prevents recruits from arriving on the day they were sworn in.

Being in a Push Division does not mean that a Recruit will not receive all the training needed to be a Sailor!! At the end of training divisions will go through Battle Stations 2-4 divisions at a time, therefore the divisions of a PIR group are staggered in training. They do not start training at the same time so they will not finish at the same time but they will graduate from Boot Camp together. 

The first 4-11 days after a new recruit arrives are Processing Days (P-days). P-days can last up to 14 days for some recruits if they have to wait for additional recruits to arrive to fill a division. Although recruits are assigned to a ship and division upon arrival, they do not move to that ship until P-days are over. During P days they will go through dental and medical screening, have the moment of truth, and have briefings about the days ahead. They also go through the dreaded haircut. They are issued their NWUs, blue camo, but during P-days they will wear what is affectionately called smurfs, the Navy issued sweat shirt and sweat pants, until their uniforms are returned to them with their name tapes sewn on. They are also issued 2 sets of PT gear, Navy shorts and a yellow shirt. They have to wear the PT gear under their smurfs.

During P-days they are issued a Recruit card. This is like a gift card with $150 on it that is deducted from their paycheck. They use these cards to buy hygiene and other supplies at the Navy Exchange. P-Days concludes with a commissioning ceremony in which each division receives its guidon, the divisional flag displaying division number. This commissioning ceremony marks the official beginning of training.

There are usually anywhere from 5-15 Divisions in a graduation group and they can arrive at RTC over a week a part. Since they are on a staggered schedule, they all get the same training though

 There are three sequences of divisions number at RTC: 800-series divisions are the divisions for the special warfare candidates, and include SEAL candidates, SWCC, and several other classifications.

900-series divisions are the performance divisions, and includes three types: the Band/Bluejacket Choir/Drill team, otherwise known as "Triple Threat" (the musicians, singers, and drill team), the "Sticks" (those who carry the state flags), and the Ship Staff/Honor Guard.

All other divisions numerically start at 001 at the beginning of the fiscal year and are numerically consecutive until the next fiscal year starts. Thus division 001 is placed in TG 01. Division 801 is the first 800 Division and Division 901 is the first 900 division and they continue with consecutive numbers as well until the next fiscal year as do the lower number divisions.