I think this may help clarify a bit, below is a definition of Highland Doublet from wikipedia:

Doublet is also a term describing a type of jacket worn with formal highland dress. This garment is similar to a mess jacket, with buttoned gauntlet cuffs, short or no skirts, and with or without lapels. It may have a row of silver heraldic buttons on each side. It may be worn with a lace jabot and cuff set, and a high-buttoned waistcoat. It is typically made of velvet or wool, with satin lapels, and may feature epaulettes. The highland doublet is jacobean in style and may date to that period or earlier.