Standardisation of 'offer maps', 'contact opportunity maps', 'loneliness/connection event and organisations'

In Germany there are at the time of writing about 12-14 different contact opportunity or offer maps. Other countries are developing theirs as well, like in the UK, France or Sweden.

It would be great to discuss a best practice for labelling and designating the components of such maps. What filters, labels, categories are most useful and meaningful both to social support workers and lonely people themselves. What technical base is the best to build a map from? What data should be included?

With what data protection disclaimers can a sharing practice amongst regional and local information provider be established.