Arabian Name Guide:

Before 2002
"Family" names occasionally found
Prefixes are rare
No more than 17 characters (including spaces)
No more than 3 separate words
No numerals (Roman or Arabic)
No Sr. or Jr.

After 2002
No more than 21 characters (including spaces)
No more than 4 separate words
No  prefixes or suffixes
No numerals (Roman or Arabic)
No Sr. or Jr.
No horse will be registered by a name which has exactly the same spelling as a name already registered
No Punctuation, apostrophes, and diacritical markings or symbols may not be used.
The only valid characters are capital letters A through Z, dash and space.

England-bred
Often have two word names including a descriptive adjective and a noun
Egyptian-bred
Usually have longer Arabic names w/ 2-3 words
Ibn (son of), bint (daughter of), bint bint (granddaughter of) sometimes used
Poland-bred
Often given one word names in language of country of origin
Tend to be named with first letter of dam's name   
Russian-bred
Often given one word names in language of country of origin
Customarily start with first letter of dam's name
Spain-bred 
Often given one word names in language of country of origin
United States
Names limited to 17 spaces