capitalising

Capitalising (American English: capitalizing) refers to the use of uppercase letters in writing. The practice serves to mark word boundaries, indicate emphasis, or signal syntactic or semantic categories such as proper nouns. In most languages that use the Latin alphabet, capitalization is governed by orthographic conventions rather than phonetic rules.

In English, capitalization follows several core rules: capitalize the first word of a sentence; capitalize proper nouns (names of people, places, organizations); capitalize days of the week, months, and holidays; capitalize the pronoun I; capitalize acronyms and initialisms; the first word of a quoted sentence; and some formal titles when they precede a name (e.g., President Smith). Title case practices vary by style guide.

Spelling variations reflect regional usage: capitalise is the British English form, capitalize is American English. In titles, some guides use title case, others sentence case, and many follow specific style manuals (APA, Chicago, MLA, AP).

Other languages differ in their conventions. German capitalises all nouns, a feature not shared by English. In computing, capitalization is a binary attribute of characters; case mapping and Unicode case folding affect text processing and search. Excessive capitalization is often perceived as emphasis or shouting in online writing.