Receipts- ok to delete??

I have a quick question. I discovered a folder with "receipts" it seems to be for programs that I have installed. What are these used for? Can I safely delete them? Do I need them for any reason?
thanks for the help
ED

Do not delete them. If you do, you will not be able to update your software. The receipts are used in keeping track of the software versions that is installed on your system.

I believe for some things they are used when you repair permissions also.

rman said:

Do not delete them. If you do, you will not be able to update your software. The receipts are used in keeping track of the software versions that is installed on your system.

Click to expand...

Outstanding catch rman!

Thanks!!!

cradom said:

I believe for some things they are used when you repair permissions also.

Click to expand...

That is true also.

I had a question about this as well. Being the Mac newbie I am, I deleted all the receipts and found that Repair Permissions wouldn't work. I got everything back to normal now but I have a related(though probably dumb) question: is it safe to delete the receipts for programs you no longer have? For example I trashed Mail and Dictionary, so would it be okay to remove the receipts for those two apps? Thanks.