Originally Posted by
Sloppy Link
Army rules are as follows....... The first row should be central for the first and subsequent ribbons until the breast pocket width is complete. In the case of some individuals, this may be up to five ribbons. Once the first row is complete, each subsequent row should start on the extreme left as worn until complete and so on. Medal ribbons should not be obscured by the lapel. In simple terms, the collection should resemble a right angled triangle and not a pyramid.
The Army changed their policy in Oct 10 with subsequent rows now being mounted centrally (until the lapel comes into play). One of the reasons given was that NATO and UN medal ribbons are not the same width as UK ones which results in uneven rows which look better centralized.
References are D/DPS(A)/25/12/00/PS12(A) dated 15 Oct 10 and Army Briefing Note 10-12 dated 2 Feb 12.
As an aside both the Army and RAF regulations mandate a gap between rows (for fewer than 5 rows). Although, military tailors don't appear to bother with this.