1. lettermark - Noun
2. lettermark - Verb
(marketing, communication, typography) A text-only logo consisting of the initials of a brand name or business.
(US, politics) The designation of funds from the federal budget for a particular project created in response to a letter from a member of congress to an official in the executive branch who is responsible for authorizing appropriations.
(US, politics) To obtain a lettermark on funds from the federal budget by sending a letter (from a member of Congress) to the appropriate official in the executive branch who is responsible for authorizing appropriations.
To mark (something) with one or more letters of the alphabet to indicate its brand or category.
Source: en.wiktionary.org