When I try to add new category name like medical & health, I received an error message that category name is not valid. Actually I type the category name like this: medical_&_health because the underscore will be replace with space. The problem is now the ampersand(&) sign is not a valid value for category name.

Can someone tell me how to make an ampersand sign or any other sign become a valid value for the category name.

Thanks in advance..