This page includes spelling and capitalization rules for commonly used technical terms.
No hyphen.
homepage
One word.
Internet
Capitalized in all uses.
log in, login
Two words when used as a verb, one word when used as an adjective or a noun.
log out, logout
Two words when used as a verb, one word when used as an adjective or a noun.
offline
One word, no hyphen.
online
One word, no hyphen.
sign in, sign-in
Two words when used as a verb, hyphenated when used as an adjective or a noun.
sign out, sign-out
Two words when used as a verb, hyphenated when used as an adjective or a noun.
username
One word unless describing a label in the user interface.
voicemail
One word.
web
Lowercased unless used at the beginning of a sentence (e.g., website, webpage, webinar, webcast, web-based, web address, web browser).
webpage
One word.
website
One word.
World Wide Web
Capitalized in all uses, but the shortened form (the web) is lowercased.