Possible Clues:

• Texted ''ta ta''
• Texter's "Speak soon"
• 'C u on da flipside!'
• 'Gotta go,' in textspeak
• Modern farewell letters
• "Until next time," in instant messages
• 'Gotta go,' in chat rooms
• Quick goodbye?
• Texting sign-off
• 'Bye,' in a text