> [Can you tell us about the secret underwear?]
heh. i'd tell you but then they'd have to kill me.
my knowledge of garments is second-hand because that part of the indoctrination doesn't occur until one gets one's temple endowment, and *that* part of the indoctrination occurs frequently at about the time one goes on a mission, gets married, or reaches young adulthood unscathed by either of those activities. i had long since left the church by the time i reached young adulthood.
however, the church site has some info for the curious. if you have any other, specific questions about garments i may be able to answer them.
------- http://www.mormons.org/basic/temples/Garments_EOM.htm
The word "garment" has distinctive meanings to Latter-day Saints. The white undergarment worn by those members who have received the ordinance of the temple Endowment is a ceremonial one. All adults who enter the temple are required to wear it. In LDS temples, men and women who receive priesthood ordinances wear this undergarment and other priestly robes. The garment is worn at all times, but the robes are worn only in the temple. Having made covenants of righteousness, the members wear the garment under their regular clothing for the rest of their lives, day and night, partially to remind them of the sacred covenants they have made with God.
The white garment symbolizes purity and helps assure modesty, respect for the attributes of God, and, to the degree it is honored, a token of what Paul regarded as taking upon one the whole armor of God (Eph. 6:13; cf. D&C 27:15). It is an outward expression of an inward covenant, and symbolizes Christlike attributes in one's mission in life. Garments bear several simple marks of orientation toward the gospel principles of obedience, truth, life, and discipleship in Christ.