http://foot.ie/threads/147164-Eligibility-Rules-Okay?p=1805274&viewfull=1#post1805274
rticle 5 of the FIFA Regulations Governing the Application of the Statutes (Principle)
Notion of permanent nationality
Yann first clarified that "permanent nationality not dependent on residence" can refer to both nationality from birth (automatic) and nationality acquired via familial inheritance or a naturalisation mechanism. Article 5.1 is specifically worded the way it is to distinguish from temporary nationality dependent on residence and to preclude the latter form of nationality from rendering players eligible to play for international teams. He said that the mention of "residence" in this article has nothing to do with the fact that most states require an applicant to reside on their soil before naturalisation, nor does it mean that naturalisations cannot be considered permanent and not dependent on residence; it's referring to something else.
To provide an example of a temporary nationality (dependent on residence), he mentioned the Vatican Swiss Guards who receive the Vatican nationality during their stay in Rome but lose it when they leave. So, as I was saying, naturalisations can and do fall under the "permanent nationality not dependent on residence" umbrella too (unless they're temporary and/or dependent on residence for a temporary duration whilst the holder resides in the relevant state), but obviously further invoke article 7 as they will, by their nature, amount to the acquisition of a new nationality not automatic from birth. (Article 7 is invoked when a permanent nationality not dependent on residence is newly acquired at any age post-birth and secondary to an already-held birth nationality or birth nationalities.)