bip3: clarify number assignment

Author: jonatack

bip-0003.md

@@ -236,7 +236,8 @@ formatting requirements specified above and should be provided as a file named w
 BIPs that (1) adhere to the formatting requirements, (2) are on-topic, and (3) have materially progressed beyond the
 ideation phase, e.g., by generating substantial public discussion and commentary from diverse contributors, by
 independent Bitcoin projects working on adopting the proposal, or by the authors working for an extended period toward
-improving the proposal based on community feedback, will be assigned a number by a BIP Editor. The BIP Editors should
+improving the proposal based on community feedback, will be assigned a number by a BIP Editor. A number may be
+considered assigned only after it has been publicly announced in the pull request by a BIP Editor. The BIP Editors should
 not assign a number when they perceive a proposal being met with lack of interest: number assignment facilitates the
 distributed discussion of ideas, but before a proposal garners some interest in the Bitcoin community, there is no need
 to refer to it by a number.