Ideally this will create a ambiguity and parser will ended up with undefData . You have to talk to data source and get agreed with delimiter , release characters and quoted release characters
In your examples if delimiter [ | ] pipeline and you have field with [ | | pipeline then it should be addressed as below from source file
john@d"|"e | 24 | john | doe - Quoted release character
john@d|e | 24 | john | doe - release character