For users attempting data entry for a datasource, if they can't input a "contains within" entry to find the source they are looking for, the likelihood of populating the proper entry options is very low and the the function of the datasource is greatly limited only to those who know the exact source entry, ie the creator.
For users attempting data entry for a datasource, if they can't input a "contains within" entry to find the source they are looking for, the likelihood of populating the proper entry options is very low and the the function of the datasource is greatly limited only to those who know the exact source entry, ie the creator.