Imperial Tramways Company Limited
As far as I am aware, the Imperial Tramways Company Ltd allowed each of its tramway concerns full control over the design of uniforms, badges and buttons. This was in marked contrast to the British Electric Traction Company Limited, an organisation which imposed a strict house style on almost all of the numerous tramway systems that it either owned or controlled. Of the Imperial’s subsidiary companies, examples of badges that clearly bear the mark of the system — rather than Imperial - are known for the Bristol Tramways and Carriage Company Limited, London United Tramways, and Middlesbrough, Stockton and Thornaby Electric Tramways. The latter system was actually worked directly by the ITCo, and it appears that the uniforms bore ITCL script-lettering buttons (see link), even though the cap badges were marked with 'MS&TET'; licences have also survived that somewhat bear both ITCoLtd and MS&TET markings (see link).
The precise usage of the licence illustrated below is uncertain, and though it may have been issued to tramway motormen, it seems more likely that it was used on one or more of the Imperial’s many bus operations.
Possible tramway-era driver licence
(with thanks to Mr Tait)