hello,

What's the meaning of parameter's red border ?

thanks!

it means that the parameter is bound to viewport ladder handle
so if you are in Show Handle mode in viewport (Enter) then MiddleClick+drag ladder will control bound (red border) parameters

you can set/unset it by RightClick on parameter name and choose
More/Bind to Viewport Ladder Handle
or
More/Unbind all Viewport handles

thank you for reply!