Title/Caption logic

[iSilentP]

Is there a way to delete (remove) the "Caption" data in an image if the "Title" data has the same value?

For example:
If Caption == Title set Caption == "" (or NULL)

All the images I need to modify are in Lightroom, so I suspect I have to run the EXIFTOOL command from the terminal and then also somehow have LR acknowledge the changes s and update the library.

[StarGeek]

Programs don't always tell you the names of the real tags. Instead, they use a description and will fill it from multiple possible tags.

There are several tags that could be called "Title" and "Caption" depending upon the program you are using to read the data. "Title" could be Title or it ObjectName. Or it could be a bunch of others if you are reading Windows Properties (see Windows Metadata).

"Caption" might be Caption-Abstract, Description, or ImageDescription.

Use the command in FAQ #3 to locate the tags you want to check.

Once you figure out the correct tags, your command would be something like this. Change Title and Description if need be.
exiftool -if "$Title eq $Description" -Description= /path/to/files/

You don't mention your OS, so the command might need modification. The above command is for Windows CMD. If you are using Mac/Linux, change the double quotes into single quotes.