rack + PDU ground confusion

Hi,

I'm looking at these two units:

• small rack

• power strip

and this part of the PDU technical details confuses me:

Grounding on aluminium profile

Does this mean that this particular unit provides grounding for the whole rack (through the plug and wallsocket) just by installing it and thus a separate grounding wire isn't needed? (Which would be convenient)

I checked a couple of other units but they don't mention anything about ground other than for the actual sockets.

Is this a common practice or just a mistranslation and I'll have to run a ground wire (to, I guess, a lug somewhere in the rack)?

Now, while I was writing this my brain came up with this: it must be a mistake because if you were to install more than 1 of these, you'd end up with multiple ground points, am I wrong?

While we're at it:

• if the rack is grounded, and has a patchpanel bolted in, but maybe there's some coating/paint on mounting rails/brackets, is this enough to ground that patchpanel or it needs to be done through the lug/wire (like here)?
• if the patchpanel is filled with shielded wires and is grounded, is it better to use unshielded patchcables (panel-to-switch and wallsocket-to-device) to avoid double grounding OR it's assumed that cables are always grounded at patchpanel and nowhere else and we can use shielded cables everywhere without grounding loop issues?

Thank you for your help.