AABB = A 4 letter .com domain name which contains only 2 different letters, where “A” and “B” symbolically represent two different letters from A-Z. Examples include: CCDD.com, DDJJ.com, MMXX.com, ZZGG.com

ABAB = A 4 letter .com domain name which contains only 2 different letters, where “A” and “B” symbolically represent two different letters from A-Z. Examples include: CDCD.com, DJDJ.com, MXMX.com, ZGZG.com

Palindromes = A 4 letter .com domain name which contains only 2 different letters from A-Z. Examples include: CDDC.com, DJJD.com, MXXM.com, ZGGZ.com. Palindromes are commonly referred to ABBA-type LLLL.com's.

Triple Letter = An LLLL.com containing three of the same letter. These are sometimes referred to as Triple letter repeats in the case it is of an AAAB or BAAA letter pattern. Examples include: SSSJ.com, SWWW.com, HHGH.com, IJII.com Notice how each of these examples showcases the Triple Letter LLLL.com differently. These are all considered Triple Letter LLLL.coms.

VVVV = A 4 letter .com domain name which contains four vowels. Examples include: AEIO.com, EUOU.com, IOUI.com, EAUU.com