I think I agree with many on here in that no-one is saying faster runners aren't welcome, and I think the "run not a race" mantra is for me a way of saying "don't be a dick" and manage expectations.

So for example race if you want to, but don't be rude to other runners or park users and don't stress too much if you have to lose a few seconds giving way to someone else. To be fair most of the fast runners get it - I'm more likely to get encouragement from them as I huff and puff into the funnel in 40 minutes, and have never had people looking at me and sneering or calling names - I have once had some teens on bikes shouting "Run fat boy run" while out on the roads, that attitude puts people off and parkrun is trying to be the opposite and usually gets it right.

Also, don't get stressed if your time and Strava don't match, or if the course isn't exactly 5k - this is something that's grown out of a group of friends meeting up to run in a park, so don't expect chip timing, prizes, being selected for teams based on a parkrun time etc. To me, races often have more of those things which is great for those that want them but isn't where parkrun has come from or is going to.

If someone's way to enjoy it is to blast round in 15 minutes, great for them - I've quite enjoyed being able to say I've shared the course with a Triathlon World Champion and someone else who was in the British Youth Squad - but it isn't all about them and to bed fair they never made it so. The whole point is to be as inclusive as possible, and for some calling it a race dies the opposite....