pseudonymous (adjective) 

Pseudonymous (soo-DON-ih-mus) means having or using a fictitious name. As I used it today: “I have observed that there is another percentage that is equally reliable and yet rarely discussed: Ten percent of every customer base is costing the business money. Let’s call it Masterson’s Law in homage to Michael Masterson, an earlier pseudonymous incarnation of yours truly.”