Adding metadata / identifier data to a CSV file?

Question

Is there a way to add a \"tag\" (add a unique metadata/identifier) to a CSV file without affecting the contents or ability to read/write the file?

I am using Python, but

Answer 1

In case you are not sure that all possible readers/writers of the file will be able to interpret (and preserve) comments, create the tag in a second file using some name convention that links them. Example:

myCSVFile.csv
myCSVFile.csv.tag