Mikael Dullord was a convenient alias used by Codringher when he felt like keeping his true identity a secret. Notably, he tried to use it, unsuccessfully, when Schirrú came knocking. For some time, Geralt also thought Fenn was an alias, but he was mistaken.
“
'The Honourable Mr. Codringher?'
'The master's away on business,' said the lawyer, assuming the expression of a halfwit and speaking in a slightly squeaky voice. 'I am the master's butler. My name is Dullord, Mikael Dullord. How may I server your honourable selves?'
”
— pg(s). 157, Time of Contempt (UK edition)