What's happened to men's collars?

There are now not just spread collars but medium spreads and extreme spreads, and not just button-down collars but abbreviated button-down collars and short, rounded button-down collars.

There is the return of the snap-tab collar, which Hamilton, a 130-year-old high-end shirt maker in Houston, is aggressively promoting for spring.

Thomas Pink is among the brands launching "dressy" button-down shirts meant to be worn with suits and ties, traditionally a no-no.

The least familiar, and therefore most shocking to the eye, are the extremely short collars some designers have shown on runways over the past two years.