ADM = Administrative
TMP = Template
These two cannot be changed nor removed (you can only rename them)
OPE = Operational = all other project types, that you may define on your own.

Thank you for your reply babynus.
Yes, I read them but where can we use the ADM and TMP project types?

In user guide for ADM:
"Type of project to follow non productive work : holidays, sickness, training, …"
How they can be projects? Surely, I skip something with that.

In user guide for TMP:
"These projects will not be used to follow "some" work.
They are just designed to define templates, to be "copied" as operational projects."
If the TMP project types use just copy, why writes "some". So In projects, can we follow the some works with TMP project types?

Project Type is used on ... Project.
Activity Type is used on ... Activity.
Ticket Type is used on ... Ticket.

It's not my question.

"Type of project to follow non productive work : holidays, sickness, training, …"
How they can be projects?

They are not really project, but object Project is used to follow such non productive work.

"These projects will not be used to follow "some" work.

You should read "These projects will not be used to follow any work.

"Type of project to follow non productive work : holidays, sickness, training, …"
How they can be projects?

They are not really project, but object Project is used to follow such non productive work.

"These projects will not be used to follow "some" work.

You should read "These projects will not be used to follow any work.

I start to use Projeqtor and I cannot generate right Template project. My new generated Template projects are visible in Planning.
This is true in both, my local Projeqtor and Demo Projeqtor on your site. Administrative projects aren't visible in Planning.
Do I make something wrong?