How to update the local tags ?

Hi aHaSaN,

check out the wiki for approved or commonly used tags. Osmose (i.e. via the link posted by az09) can help you identify and edit bad tags.

Here's an example how to proceed: http://www.openstreetmap.org/way/295391114 is identified in Osmose as a bad tagged building. Let's have a detailed look at the tags:

building=Library
name=Library Bhaban

If you search the OSM wiki for library, you will find https://wiki.openstreetmap.org/wiki/Tag:amenity%3Dlibrary So the official tagging for a library should be

amenity=library
name=Library Bhaban

You might leave the building tag and change it either to building=yes or building=civic - the wiki mentions libraries as an example for civic buildings, however it doesn't seem to be widely used, so there is always some room for interpretation ;)

Another example for this ATM machine: http://www.openstreetmap.org/node/4363320727

Current tags:

amenity=atm booth
name=BRAC Bank Ltd

Again search the wiki for atm and find the corresponding page: https://wiki.openstreetmap.org/wiki/Tag:amenity%3Datm - to fix the error you would just have to change the tags to

amenity=atm
operator=BRAC Bank Ltd

If you have any more information (see wiki for many other possible keys) you may add it too.

Last but not least let's have one of the building on the university campus (there seem to be a lot of errors): http://www.openstreetmap.org/way/295545678

building=Academic
name=MBA Building

As it is part of Dhaka University I would follow the tagging guidelines for universities in the wiki (https://wiki.openstreetmap.org/wiki/Tag:amenity%3Duniversity), so appropriate tags here should be

building=university
name=MBA Building

And like before any more information you are able to provide.

Hope this helps, happy mapping.