The quote prices what you expect the expenses to come to. The job’s Expenses tab records what they actually came to — parking, fuel, catering, a rented lens, a courier — each with a date, a category and who paid, measured against the figure you quoted.

Camera & gear rental, crew & labour, travel & transport, catering & craft, art & props, accommodation, permits, expendables, post-production, shipping and the rest — the categories a production actually spends against.
An expense estimate is an ordinary line on the quote, so the client reads the figure before the job and agrees to it. What is actually spent is itemised on the Expenses tab underneath it, and the two are shown side by side.
Out of pocket means you paid and the job carries it. Rebill to client means you paid and you are charging it on. Client paid direct means they paid that supplier themselves.
None, 10%, 20%, 30% or your own number, taken on equipment, crew, studio, expenses, or any combination of them.
Out of pocket comes off it. A rebilled one lands on both sides and leaves it where it was. Client-paid does neither, because it never left your account.
They go on the quote, and the invoice offers to take the change with a version kept first. An invoice already sent is not altered without you asking.
A shared list of nineteen production categories. You can add to it, and the expense importer snaps imported rows onto the same names.
That is your choice. It is always its own line in your copy; the section can print as one row if you would rather the client read a single number.
The sandbox has jobs with expenses on them — one absorbed, one charged on, one the client paid — and a quote carrying a production fee.