I inherited a database, and want to clean house. Is there a way to find all the unused fields and value lists? I have several fields defined that I simply cannot find in the database. I'd hate to whack 'em only to find out they were actually in use.
Start by printing the fields definitions to PDF, and print the script definitions to PDF as well. Then you can search (ctrl+f) the PDF for occurrences of the field name you want to delete.
Then, to check which layout its on, go to File > Access Priveleges > Overview. Click on the field you want to delete (in the right most column). Then, the layouts on which it appears will become highlighted in the "Layouts" column.
Don't forget to check the relationships as well. You'll have to click through each one to check if it uses the field.
You'll also have to check the value lists one by one.
The problem with the above methods is that they only check for references to the field from within the same file. None of these methods tell you if another file references that field via a value list, relationship, field calculation (or field validation), or layout.
If you have a copy of FileMaker Developer, you can go to "File > Database Design Report" and run that. It will produce a fairly comprehensive report that summarizes where your field is referenced. However, I don't think the DDR mentions references from other files, or if it does, then it doesn't catch every type of external reference.
Finally, you can also look on the web for plug-ins that document your solution. Brushfire is one that comes to mind.