RICEF is an acronym in SAP world which apparently was not invented by SAP. And so it is an unofficial acronym. Which does not mean it is an illegal or secret acronym given that it has become a term in proper usage in more and more projects.
RICEF means Report , Interface , Conversion , Enhancement , Form and, basically, refers to any kind of development that might be needed in a SAP project.
Report refers to reports, ALVs, transactions and all kinds of interactive stuff.
Interface works as a means of transporting data between SAP and other systems. So it relates to IDOCs, ALE, EDI, RFC, PI things, etc.
Conversion refers to data conversion, i.e. data input through BDC, DI, LSMW, etc.
Enhancement refers to all kinds of user-exits, BADIs and their ilk;
Form are, of course, the famous Layouts and the most recent Smart Forms, Adobe Forms and integrations with MS Office.
And just five little letters can describe all the development types possible in SAP.
It is used to address the need to identify the different developments in a project unambiguously. Note this example from a short dialogue between an operational consultant (green) and an ABAP consultant (purple):
Green - We need a new RICEF in FI. Purple - Another one? Why? Aren’t there enough already? Green - No. We always need more. Purple - And what is this new RICEF called? Green - F451. Purple - Damn it, another form.
Greetings from Abapinho.