Electronic - Harold and Evelyn
Here is a pdf outlining how IEA and RCA annotation is done at MGI
EVELYN: According to the GO Consortium guidelines any GO annotation that is created by electronic strategies should have appended to it the GO evidence code 'inferred from electronic annotation' (IEA). Electronic annotation is a very efficient way of annotating large datasets with GO terms. Each of the GOC databases uses a series of GO mapping files ... (will write more 2moro...Ev)
Figure 1. The large-scale assignment of GO terms to UniProtKB entries uses existing information within UniProtKB database entries and series of manual mappings.