In the browser-based donation page of SF, an organization can set up the designations or gift types that the donor chooses from a drop down box, or includes after the amount in the text-based gift message. Examples are Tithe, GeneralOffering, BuildingFund, etc.
We had an interesting scenario where a donor was entering "amount designation amount designation" in the text message to split their gift. We later found that only the first amount and designation were being received and recorded. The second gift was never included. Of course, with the browser-based giving, the user can click the add gift button and continue to enter amounts and choose designations, so they never experienced this issue.
Therefore, a few feature requests came from this one discovery: