Non Sharing Data Rollover Topup

[Jp]

I phoned o2 to top up my data with 2GB. Recieved the following text:

O2: You've topped up your data with 2GB Non Sharing Data Rollover Topup. This will keep going until your next bill date. Anything you haven't used by then will roll over into next month's data. And we'll let you know if you're close to running out.

I topped up because I currently need to use wifi hotspot for 3-4 days so that I can browse the net on my laptop rather than on my phone.

I want to know what exactly they mean by "Non Sharing"? As there are no clear terms and conditions or information on their website. I am worried this might be their way of scamming the public. It was never mentioned to me that it was Non Sharing data before purchasing. Why have they refused to put more information on the meaning of Non Sharing data? Has anyone had issues trying to use add on data as wifi hotspot on personal laptop?

[MI5]

It's nothing to do with tethering, that's still OK to do.
The non sharing bit means you can't share the data with someone else on a sharer plan.
https://www.o2.co.uk/sharer-plans