One is allowed to set user attributes via Grid - Active Nodes - User Attributes tab
The same can be set in <conf>/attributes.properties file of ana QB build agent, but that way needs agent to be restarted...
For the readability in a file we can use empty lines and/or comments (lines beginning with the "#"-sign)
But when we save user attributes via web-interface, all empty lines are vanished and comment lines are suffixed with the "=" sign.
It's obviuos that empty lines nor even comments are not supported while saving.
It's annoying behaviour and unconvenient.