How can I change the Last Name is required. The last name field must be entered? to blank

Dear All,

We in our organization do not follow the First, Middle and Last name format. We just use the full name.

The system is not allowing us to keep the last name field blank by displaying this message:

Last Name is required. (1000,807)

The last name field must be entered.

Is there any way I can turn this message off and leave the Last Name Filed Blank?

Thank you,

Alex