Recently I was working on a Service Request, where the address book normalization was not able to normalize simple 10 Digit numbers. I tried about half a dozen normalization rules, trying to make sure that the pattern would capture the phone numbers, but kept failing continuously.
As I was reading Ken’s Blog ( See: http://ucken.blogspot.com/2015/05/skype4b-address-book-normalization.html ), I noticed that the default E164 rule was indeed missing
(UPDATE 2015-Aug-13: Hany Elkady noted in the comments below that removing the E164 rule seemed to stop AD phone numbers already stored in E.164 format from appearing in the address book. I personally haven't seen this occur but you might want to leave that rule in place.)
I decided to rebuild the default Normalization rule by running the following and noticed that Normalization started to occur.
New-CsAddressBookNormalizationRule -Parent Global -Name 'Generic_E164' -Description "Generic_E164" -Pattern E164 -Translation NULL
Since then our Documentation for New-CsAddressBookNormalizationRule ( See: https://technet.microsoft.com/en-us/library/dn985803.aspx) has been updated
Note:E164 is a well-known keyword which translates to tel:+digits-that-match. If E164 is specified and the phone number doesn't need to be translated then NULL is an expected response
Note:If the pattern is E164 then NULL is a valid value for Translation since the number doesn't need to be translated.