2022
[As an experienced Local Guide, I now sometimes come across inconsistencies or notice that errors have been made that I used to make myself when I started out. So I am publishing a few 'best practice' posts, in the hope it can help others.]
A short tip, this time, but a useful one, as it will prevent you from unintentionally adding incorrect data.
Sometimes you might want to add a point of interest (POI) which does not have a house number, e.g. a tourist attraction or viewing point, a statue or a glass recycling container. In those cases, the main thing you should know is that you should not enter the ZIP code when entering the address. If you do enter it, the algorithm will interpret the number you entered as the house number and then add that same number once more as ZIP code. You then end up with something like 'Main Street 1234, 1234 Anytown'. If you enter only street name and town, it will get created correctly as 'Main Street, 1234 Anytown'.
Other posts in this series:
Best Practice: Entering Opening hours
Best Practice: ALL CAPS / all lowercase
Best Practice: Correcting pin location
Best Practice: Choosing a more specific category
Best Practice: Submit changes one by one
Best Practice: Find the right zoom level
Best Practice: Reporting duplicates
Best Practice: Correcting errors you accidentally made
Best Practice: Filtering 'Check the facts'
Best Practice: Find the right category
Best Practice: Create on mobile / Complete on desktop
Best Practice: Improve your reputation
Best Practice: The best order for suggesting edits
Best Practice: Get rid of legal names
Best Practice: Attempts to add bus stop or train station
Disclaimer: the practices described here as best practice are my personal interpretation, and I don't claim any level of official endorsement.