Requêtes Overpass avancées :

Extract all features without a name tag:
name!=*

Extract all features that has a name tag:
name=*

Extract all name tags which contains a particular set of words in the name:
name:ram
name~ram

Extract all name tags which does not contain a particular set of words in the name:
name!~ram

Edits by a user:
user:osmusername

Combine two queries:
Extract all features with name tag but without the word View in the name
name=* && name!~View

All buildings touched by a user in the last one month:
user:osmusername && newer:1month && building
user:osmusername && newer:"2016-01-28T19:01:00Z" && building

source : http://www.openstreetmap.org/user/ramyaragupathy/diary/37884
voir aussi : http://wiki.openstreetmap.org/wiki/Overpass_turbo/Wizard

[Edit]
Une requête que j'ai longtemps cherchée et qui semble marcher. Pour chercher un nom donné dans tous les tags :
~"."~"Le Nom Cherché"