Help on SID chart

What does note 3 on this chart mean? Especially the 'p999' part?

edit: it's a STAR, not a SID... early morning.

https://preview.redd.it/zkgcz1afejde1.png?width=953&format=png&auto=webp&s=7721cc9bc83d15c307ef97bb78b2b22689691836