Possible Clues:

• Possible response to 'cya'
• Equivalent of 'cya' in a text
• "k bye!"
• Texter's "Bye now"
• Texter's "Ta-ta"
• 'Chat another time!' in an I.M
• "Bye for now," in texts
• Texter's farewell
• 'G2G'
• Texter's sign-off