I need to standardise my 'sources' as, over time, they have lost some consistency.   I can't seem to find the answer in the FHUG knowledge base.  

I THINK I can change them this way (but I do have thousands of records, so want to be absolutely sure before I commit):

Go to records window, click on 'sources',  click on the name of the source which opens a 2nd window.   I can then make changes in this window.  However, does this change ALL the relevant sources?   If it does, what happens if there is then a duplication of source names?

I'd appreciate any thoughts/advice

Maureen Mitchell