When councils place lines and signs, they must meet the requirements set by government in the TSRGD. The best known requirements are that yellow lines must have end caps, and that yellow lines must be continuous, not broken.
That’s not quite accurate, though. Since 2016, there has been no requirement to have end caps on yellow lines (and before then, a missing end cap would not normally cause a ticket to be cancelled).
Breaks in lines is a little different. Lines are still to be painted without breaks – rather than being painted as a deliberately broken line. This does not mean, though, that they must remain in perfect condition. Lines still apply even when damaged, especially when the damage or wear and tear is minor – what is required is that they are still visible enough to show the motorist they are there.