Excerpt from the link above:
For example:
The highest ranked candidates are invited during rounds of invitations. If we issue 3,500 invitations during a round, the system will pick the top 3,500 candidates at that time. The cut-off for the round is set by the CRS and submission date of the 3,500thcandidate. It could look something like this:
Rank CRS Profile submission
(Date and time) Status
3498 422 October 14, 2016 at 20:40:56 Invited
3499 422 February 5, 2017 at 11:32:01 Invited
3500 422 March 27, 2017 at 08:12:23 Invited
3501 422 March 27, 2017 at 9:54:39 Still in the pool
3502 423 June 3, 2017 at 22:57:12 Still in the pool
I will consider the highlighted text in red as typographical error. I believe the cut-off in the example above is 422 and that 423 should be Invited.