Noun
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byte order mark (plural byte order marks)
(computing) A character indicating the endianness of a string of text; specifically, the Unicode character U+FEFF ZERO WIDTH NO-BREAK SPACE.
byte-order mark
Byte order mark/Unicode sniffing For both serializations of HTML (content-type "text/html" and content/type "application/xhtml+xml"), the Byte order mark (BOM) is an effective way to transmit encoding information within an HTML document. Source: Internet
Encoding defaults An encoding default applies when there is no external or internal encoding declaration and also no Byte order mark. Source: Internet