Biblatex defines data annotations, which allow extra information to be added to fields i.e. adding corresponding author marks.

E.g.

@Article{
  author     = {Joe Doe and Mary Jane},
  author+an  = {1=corresponding; 2=highlight},
}

can be used to produce "Doe*, J. & Jane, M", given appropriate formatters for the various annotations.

Currently using \author+an in a .layout results in "Joe Doe and Mary Jane+an" rather than "1=corresponding; 2=highlight".

Minimal support (to access annotation during exports):

• Support in the .layout definitions to handle fields with special characters +:.

Full support would need a scheme for parsing and using this information for formatting in custom .layout files.