Cento is a piece of writing, esp. a poem, composed wholly of quotations from the works of other authors. It like a patchwork quilt, a fabricated whole from scraps from other places, people and times.

For me I also see Cento pieces like collage, disparate fragments of texts, images, quotes, colours brought together, moved around to create something totally new and unique which pulls meaning from the parts in construction but together go beyond their initial meanings and purposes.
Alchemy comes to mind as well as conjure. Magic.
Is this Mixmoir a Cento? No as I’m using my own text and anyone else’s that appear within it are credited. But I think there is an element of Centoism within the text as I pull from my body of work for the past 6 or 7 years to construct it. Also the different genres of writing and art that are going into the mix to create the whole is Centoist in practice, maybe.
This is an example of a Cento I created recently, which I think will be included in the Mixmoir, eventually.
Cento for black birds pushing against glass*
The first breath comes from early morning blossom.
Rain falls short. Look. The unbuckling sky. Rain.
There’s an old pain. The memory of water keeps
flowing heavy with blood. Bloodhounds catch the scent.
Black bodies packed into boats and the tide still rolling in.
A corpse dangling from the end of a rope. Justice they say.
And they cut off parts for souvenirs. Within these city walls
there is no room for self-love. Grin, keeping grinning at the camera.
My heart catches on fire as it could easily be my story. My body.
Along blood lines, pumped into the centre of the wound
it’s the body that remembers as tonight this river will receive
the crushed burden like black morels under foot.
Pull the earth on top of her, turn her black face away from the light.
I can not. But they’ve got the centuries’ old tradition to fall back on;
the rich white man and the black woman kept close
in the big house always ready to be split.
*Cento composed of lines from my past poems which were partly composed of lines taken from various other creatives. The title is from Lucille Clifton, and other lines are borrowed from James Allen, Kara Walker, Tafisha Edwards, Ocean Vuong, Billie Holiday, Martha Collins, and Toi Derricotte. There also a nod towards the film Monster’s Ball.