OT - subflooring for linoleum

[69Cat]

I haven't done any linoleum work before so need to know what type of board to put down for new linoleum. My porch area had porcelain tile glued directly to plywood flooring and to the wood that make up the couple of steps to the family room. I removed the tiles and now I want to put new material down to cover the glue and to finish the steps a little better. The supplier of the lino mentioned K3 board but did not know another trade name, any opinions?

Thanks,
Ken