Question

• Is there any cons of 2nd method?
  Why http://www.webstandards.org/ decided to use 2nd method
• Is first method better than first for
  screen reader users?

First

<label for="name">Name</label>
      <input id="name" />

Second

<label for="n">Name</label>
      <input id="n" />

Answer 1

The only ‘con’ is that the id is non-descriptive. For a page with little content, this wouldn’t be a big deal but for a larger page, using a descriptive ID is helpful in development. Too, ID’s need to be unique, so the single letter approach would get old at input #26 :p

As a side note, webstandards.org might have run their html through a compression utility that changes their descriptive IDs into single letters to minimize download time. e.g.

Their in-house code is your first example and the compressor spit out your second.