From the article: "Those ICRs in effect serve as a full list of every website that people have visited, rather than collecting which specific pages are visited or what's done on them."

And from another site on the same issue: "When you visit a website you usually start at the websites homepage such as www.bigbrotherwatch.org.uk/ the Government define this part of a website address (the part before the first forward slash) as communications data which they consider to be non-intrusive information." (https://www.bigbrotherwatch.org.uk/wp-content/uploads/2016/0...)

In fairness the law mandates they record the domain, it doesn't say anything about capturing more it just sets a standard for the minimum.

Given that the ISP's have now been given cart blanche to collect data that is very commercially valuable I can see some of them doing it with the hope they can sell it later.

For http sites they have access to whole url and everything that is submitted, for example all commments you write.

For https sites (green lock icon) they only know domain name, for example reddit.com

As long as the site uses https (reddit does), then the path is encrypted, the only part of the URL thing they'll have access to is the host.