Should I write “calling himself in this/that way” here?

Question

In my text I am trying to say, that it is not clear what intentions the person had, by calling themselves in a certain way (let's say Foobar).

My question is should I use "calling himself this way" or "calling himself so"?

Here is my sentence in context:

Many unsuccessful attempts have been made to explain the meaning of Foobar. To this day it is not clear what Mario meant by calling himself so.

Or:

To this day it is not clear what Mario meant by calling himself in this/that way.

Is it clear what this sentence means? I am not sure if a person can "call" himself... Perhaps I am over-thinking it.

Answer 1

I like the "by calling himself in that way" part. As @Hellion said "calling himself so" although understandable, sounds a little unusual.

Answer 2

sounds good to me.

other possibilities are "referring to himself as X" or "referring to himself that way"

Answer 3

Either would work fine.

"…describing himself thus"

might be another, more formal way of putting it - it has the meaning of "in this/that way" but it has the benefit of being terser, tighter.

Answer 4

"Calling himself so" is a legitimate, but certainly unusual, construct. If you want to avoid the unusual, you should probably go with "...by referring to himself in that way" or "...by calling himself that."