{{#if:{{{6}}}|{{DEFAULTSORT:{{{6}}} }} }}
{{#if:{{{6}}}|{{DEFAULTSORT:{{{6}}} }} }}
Yes, it is possible.
Could you fix this Template:Illustrator ? When I use that line, the page ends up sorted under "{" here.
I assumed you were trying to defaultsort Ringo Aka to section A in Category:Illustrators. If so, you were missing the fifth parameter, which was to be blank.
Checked what you did and it's good, thank you!
Question though since you've put a pipe character "|" in the SORTKEY, when should pipe characters be used in parameters? The other parameters work correctly without it.
Don't mind that. I was not sure of how defaultsort behaves with parameters, and so made that edit. To answer your question, when a pipe is used in a parameter, it sets a default value to the parameter (that is, if it is not filled, anything after pipe will be taken by default). You are free to remove it, it won't cause any issues.
Adding that pipe solved the problem. Without it, DEFAULTSORT reads "{" of {{{6}}} as the SORTKEY.
Thank you again!
Strange, it didn't cause any errors for me, nevermind. You're welcome.