Levees were/are gatherings of gentlemen held by the Monarch or his depute. Gentlemen would be presented to the Monarch at such occasions (similar to ladies being presented at Court--court being the Royal Court, and not a court of law).

There were/are strict regulations regarding dress to be worn at HM's Courts and Levees ( and State Balls and Dinners etc.) The last regulations, published by the Lord Chamberlain in 1937, stipulate the following for Highland Court Dress:

Dress DOUBLET (not necessarily buttoned) of velvet, cloth (any dark
colour) or tartan.
WAISTCOAT (if Doublet not worn buttoned up) of velvet, cloth (any
colour) or tartan - cut high.
Dress KILT.
Dress HOSE.
PLAID (either "Shoulder" - worn long round body and over left
shoulder, or "Belted" - worn on left shoulder and round waist).
SHOULDER BROOCH for Plaid.
Dress SPORRAN, any pattern, of hair, fur, or skin.
Dress SPORRAN STRAP or CHAIN, any pattern.
Highland basket hilted SWORD, black leather (or metal mounted)
Scabbard.
CROSS BELT of leather (or metal mounted) for carrying the sword worn
over right shoulder.
Dress DIRK.
WAIST BELT of leather (or metal mounted) with buckle, for carrying
Dirk. (This is optional, as Dirk can be carried on belt worn under
Waistcoat or Doublet).
Dress "SKEAN DHU" worn in hose.
PIN for apron of kilt.
JABOT, lace (lace, silk, satin or lawn stock).
CUFFS, lace.
Dress SHOES (with buckle), or brogues, black leather, for evening
wear, buckle optional.
HIGHLAND BONNET - crest or badge worn in it - with Feather or
Feathers for those entitled to them.
Note.-Highland Pistols and Powder Horn may be worn.
Gloves are not worn.