rel="alternate" hreflang="x" for a Region?

[McMohan]

Here is a site that targets the entire Middle East region. It is in English and the content is significantly same as its parent site. rel="alternate" hreflang="x" targets by country/language. AFAIK there isn't a region code nor a sub-country code.

Is writing the rel="alternate" annotations for all the countries in the Middle East an option?

[phranque]

hreflang="x" targets by country/language

http://support.google.com/webmasters/bin/answer.py?hl=en&answer=189077 [support.google.com]:

hreflang supported values
The value of the hreflang attribute identifies the language (in ISO 639-1 format) and optionally the region (in ISO 3166-1 Alpha 2 format) of an alternate URL.

while there isn't a "middle east" region code, you could do something like this:

<link rel=”alternate” href=”http://example.com/en-middle-east” hreflang=”en-ae” />
<link rel=”alternate” href=”http://example.com/en-middle-east” hreflang=”en-kw” />
<link rel=”alternate” href=”http://example.com/en-middle-east” hreflang=”en-sa” />

etc...