"unapproved equipment" query

[#1]

Hi PN,
Can you clarify please, does "unapproved equipment" here relate to regulatory approvals (if BABT still does its thing), or does it relate to PN and/or BTOR approvals for equipment?
https://www.plus.net/info2/legal/price_guide.html

Quote

Providing a restricted service 4. We may restrict your service if you do not pay your bill, reach your credit limit or where unapproved attachments have been made to your line. We will charge you £5.76 to apply/or lift any of these restrictions.

I see a lot of people use their own VDSL2 modems on PN and I was going to be going down that path myself, but noticed the above when ensuring nothing I was planning breaks T&C's. Can you please clarify what "unapproved" above means for us?
Many thanks

[#2]

Probably refers to equipment that hasn't passed the relevant technical tests (approvals) for connection to a BT phone line.
That used to be signified by a BABT sticker, not sure if that's still current.

[#3]

Cheers HPSauce  thats what i suspected too, but ive not seen a BABT green dot in years.They do apparently still exist though.
dick:quote

[#4]

In all the time I've been on these fora I've never seen a staff member respond to customers connecting third party equipment other than in a helpful and positive manner. So I will say there are problems with customers connecting iffy kit but they don't deal with it legalistically 

[#5]

I'm not actually 100% sure on this. It sounds like the other posters might be correct but I've sent an email off internally to try and find out.