Incidentally, in chat rooms

• Lead-in to a texter's afterthought
• "One more thing..." online
• "And another thing ...," in texts
• Start of a text-message afterthought
• "Incidentally," in online shorthand
• Incidentally, in texting shorthand
• "Oh, P.S."
• "Incidentally," to texters
• "I forgot 2 mention it, but ..."

Wiktionary Word definitions in Wiktionary
abbr. (alternative spelling of BTW English)