What is a line length “soft limit” and how do I interpret this in the PSR-2 convention?

It’s pretty easy:

• 0-80: Always ok
• 80-120: Acceptable (if there’s a good reason for it, e.g. a string where wrapping it would be ugly)
• 120+: Lint tools, IDEs, etc. MUST show a warning (but never an error!) since the line might be ugly/unreadable/…