From Fedora Project Wiki

This page lists the autotest system labels used by AutoQA. Labels are important when adding new clients to autotest or when writing new tests for AutoQA. You can read more at How to add autotest clients and Writing AutoQA Tests.

Platform labels

A system can have only one of the following labels. This is a restriction enforced by autotest.

i386
host has i386 architecture
x86_64
host has x86_64 architecture

Distribution labels

Much like platform labels, a system should have only one of the following labels.

fcNN
Fedora NN is installed on the host (e.g.fc40, fc41, fc42 ...).

Capability labels

A system can use one or more of the following labels. However, note that some labels may be contradictory.

virt_capable
the host is capable of using virtualization technologies (we're mainly interested in KVM)
virt
the host is running inside virtualized environment, it is not a bare metal machine

Other labels

noarch
noarch tests will be executed only on clients with this label. Adding this label to all your clients distributes the workload most equally (recommended).