For C#, check out Microsoft’s guidelines:
Do capitalize both characters of two-character acronyms, except the
first word of a camel-cased
identifier.A property named DBRate is an example
of a short acronym (DB) used as the
first word of a Pascal-cased
identifier. A parameter named
ioChannel is an example of a short
acronym (IO) used as the first word of
a camel-cased identifier.Do capitalize only the first character of acronyms with three or
more characters, except the first word
of a camel-cased identifier.A class named XmlWriter is an example
of a long acronym used as the first
word of a Pascal-cased identifier. A
parameter named htmlReader is an
example of a long acronym used as the
first word of a camel-cased
identifier.Do not capitalize any of the characters of any acronyms, whatever
their length, at the beginning of a
camel-cased identifier.A parameter named xmlStream is an
example of a long acronym (xml) used
as the first word of a camel-cased
identifier. A parameter named
dbServerName is an example of a short
acronym (db) used as the first word of
a camel-cased identifier.