Found this quote on Wiki Pedia.
The Grenadier Guards (GREN GDS) is the most senior regiment of the Guards Division of the British Army, and, as such, is the most senior regiment of infantry. It is not, however, the most senior regiment of the Army, this position being attributed to the Life Guards. The Coldstream Guards was formed before the Grenadier Guards, but that regiment is ranked after the Grenadiers in seniority as it was a regiment of the New Model Army.
The grouping of buttons on the tunic is a common way to distinguish between the regiments of Foot Guards. Grenadier Guards' buttons are equally spaced and embossed with the Royal Cypher reversed and interlaced surrounded by the Royal Garter bearing Honi soit qui mal y pense (Evil be to him who evil thinks ). Their “Buff Belt” brass clasped also carry the Royal Cypher, Modern Grenadier Guardsmen wear a cap badge of a "grenade fired proper" with 17 flames. This cap badge is to be cleaned twice a day once in the morning and once in the afternoon, as it is made from brass and a tarnished grenade is frowned upon by all in the regiment.
