Balisage is, most commonly in military applications, the use of dim lighting to enable navigation while not giving away one's position to the enemy.

It can also refer, in computer applications, to the use of markup

Markup language

A markup language is a modern system for annotating a text in a way that is syntactically distinguishable from that text. The idea and terminology evolved from the "marking up" of manuscripts, i.e. the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts...

 to enable document processing while not "giving away" one's data to proprietary software programs from which it might be hard to extract the data later.

This usage may have originated in the fact that the French version of the ISO standard defining SGML, translates the title thus:

Information processing - Text and office systems - Standard Generalized Markup Language (SGML)

Traitement de l'information -- Systèmes bureautiques -- Langage normalisé de balisage généralisé (SGML)

Presumably in consequence, Balisage is also an annual conference on XML and related markup technologies, held in Montreal

Montreal

Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...

since 2007.