What's the reminder Ted Cruz set for himself?

Ed O'Keefe of the Washington Post describes the scene inside the Senate as Ted Cruz (R-Texas) delivers his very extended remarks on "Obamacare," which began close to 3 p.m. on Tuesday. It's mostly a dull scene but also this:

And just in case he loses his train of thought, there's also a yellow post-it note that reads in blue ink: "Yield only for the purpose of a question. Be careful!"

If Cruz were to stop speaking (before he's forced to at noon Wednesday) for any purpose other than to answer a question from a colleague, it would conclude his time on the Senate floor and usual business would proceed. In this case, a vote to proceed on a bill that would continue to fund the government through mid December.