Things that aren't "true fungi"

In the literature, you see Eumycetes referred to as "true fungi". Okay, so what are the organisms that don't fit into this group? What organisms are confusingly similar, and maybe very closely related?

Wikipedia:

• Fungus § Fungus-like organisms
• Fungi imperfecti
• Pseudofungi
  • Oomycetes, the water molds
  • Hyphochytriomycetes
• Prototaxites — There's ongoing disputes over where they belong phylogenetically.
• Slime mold

Other sites:

• https://www.davidmoore.org.uk/21st_Century_Guidebook_to_Fungi_PLATINUM/Ch03_10.htm "The untrue fungi"