What goes into estimates is basically everything that has been through Treasury Board and approved and that is ready for spending. This comes in from departments and is then used to make up the appropriation bill. That process is very much done based on what Treasury Board has approved in terms of spending items.
There is also in your question a link to RPPs. Reports on plans and priorities are there to support the main estimates. The link between the two is that RPPs are tabled in time to help committees study the main estimates. I appreciate that it has caused some challenges this year because of the timing of the budget. What I think this committee is studying is whether there are ways to fix that. RPPs, by convention, were invented to help support the study of the main estimates.