Membership in the Order of Malta is limited to Catholic gentlemen, and Catholic ladies; its rank structure is divided into two noble categories-- Honour and Devotion, and Grace and Devotion. There is also a third category for non-nobles -- Magistral Grace. The definition of "nobles" as used by the Order is as follows:

The word "noble", as used in the Order of Malta, is not restricted to titled nobility, but has retained its earlier and broader sense and applies to all who are of noble status by birth or creation". (Emphasis added.)

Elsewhere the Order of Malta goes on to say:

"...an outward sign of nobility has been for many centuries the public use of heraldic arms".

I believe that the key word here is "creation". When a grant of arms is made, the recipient is, in effect, created an armiger and thus becomes a member of the nobility.

It has been suggested that Sir Thomas Innes of Learney added the phrase "...by demonstration of which Ensigns Armorial he and his successors in the same are, amongst Nobles and in all Places of Honour, to be taken, numbered, accounted and received as Nobles in the Noblesse of Scotland~~~" because confusion had arisen on the continent as to the status of Scottish grants of arms.

This confusion resulted in armigerous Scottish gentlemen seeking admission to the Order of Malta being received in the category of Magistral Grace, the lowest rank of membership, regardless of their noble status. (The commonly understood standard of nobility throughout Europe -- with the exception of the United Kingdom -- is the possession of a coat of arms, and has nothing whatsoever to do with titles.)

It was the late Col. Gayre of Gayre and Nigg who, having been made aware of this dichotomy, brought it to the attention of Lyon. (Gayre, by the way, was a protestant and therefore not eligible for membership in the Order of Malta; thus his intervention can not be said to have been self-serving.) By adding the "nobility clause", Lyon was merely asserting to his continental counterparts that a Scottish armiger, who bore arms in right of his sovereign, was of the same status as any continental armiger, and that he should be treated as such.

The whole discussion of nobility vs titled nobility is probably beyond the scope of this forum, as is "when is a peer not a peer?" (Answer: when he has lost his seat in Lords and reverts to the status of merely "titled" nobility.)