If the campaign the donation is attributed to is configured to have a "premium", the transaction will be sent to Aegis as an order (*).
If the donor creates a recurring donation, the first/immediate transaction will be sent to Aegis as an order(*). However, the following recurring iterations will be sent to Aegis as a gift and also include the sku from the "recurring product sku". Note, if you don't see the "recurring product sku" section inside of the premium section of the page builder, that is because the page is not configured to accept recurring donations.
(*) There is an override you can set that forces all transactions to be sent to Aegis as Gifts. Orders are never sent even if the campaign is setup to have a premium offer. More information can be found here, under "Treat Premium as Donation?"
Flags can be sent to Aegis as well. You can send one or multiple flags to Aegis. Flags will be included on one-time transactions as well as recurring and recurring iteration transactions.
You can specify multiple flags by separating them with a comma. Example,
flag1, flag2, flag3.