Be explicit that places aren't guaranteed

It's unlikely we'll need to prevent teams from completing, but we should still account for it!

_posts/2018-09-27-sr2019-announced.md

@@ -32,9 +32,9 @@ Rising to the top of the knockout stages is not the only way to impress the
 judges though; prizes will be available in a number of other categories to be
 announced at kickstart.
 
-If you would like to compete in Student Robotics 2019, please fill in the
+If you would like a chance to compete in Student Robotics 2019, please fill in the
 [entry form][entry-form] with the required information. All further emails about
-SR2019 will be sent to the address you provide there. The closing date will be
-*26th October*.
+SR2019 will be sent to the address you provide there. Places will be allocated on a 
+'first come, first served' basis, and the final date for applications will be *26th October*. 
 
 [entry-form]: https://studentrobotics.us12.list-manage.com/subscribe?u=1af17c2a3426de258620aae46&id=dd9ef8ad9f