R.I.P or RIP is an abbreviation of 'requiescat in pace' (Latin meaning: May He/She Rest in Peace) or in English - Rest in peace.

It's an idiomatic expression wishing eternal rest and peace to someone who has died.

I’d also suggest documenting the assumptions and constraints alongside the main analysis, even if they seem obvious at the time. A few weeks later those details are usually what explain why certain decisions were made, and it saves a lot of backtracking when the model evolves.