Status: whatever

The goal is to give a description of H.J.Baues' "secondary Steenrod algebra" in terms of formal group laws.

Baues' secondary Steenrod algebra is a certain 4-term exact sequence
of the form

A → B_{1} → B_{0} → A

where A is the ordinary Steenrod algebra.
I have described a smaller but equivalent model in
my paper.
This model does not yet have a good explanation, though.
I wonder if some notion of "formal group up-to-homotopy"
could be used to give a natural & convincing description
of it.