Cream colored spots on leaves

[roadrunner]

Charlie or Cindy,

 Do you have any idea what these spots are? I posted this condition on the forum several years ago and nobody knew what it was.  They first appeared on Rockets Red Glare and now I have at least 10 plants with them. They don't affect growth and the leaves don't discolor and fall. They stay on the plant all year. Has anyone else on the forum seen this?

Thanks,

dave