AppStream license code for public domain works

[Alexander Ploumistos]

Hello everyone,

While writing metainfo files for a few fonts, I noticed that their
creator states on his website:

"Fonts and documents in this site are not pieces of property or
merchandise items; they carry no trademark, copyright, license or
other market tags; they are free for any use."

As far as I can tell, that makes them public domain. Is it the same as
CC0-1.0 or is there another license I should choose?