https://www.openstreetmap.org/changeset/72668796
Can I just delete this Bandar Bestari boundary that is in the wrong place in Bandar Bukit Tinggi, Klang?
Or I need to do something else?
regards,
SMS
Please, just go ahead. If possible, you might want to update the boundary (or simply use a single point or node) to actually reflect the correct location in reality.
P.S. welcome back, one of the very first group of Malaysian mappers 
TQ @AkuAnakTimur. I’ll do so tomorrow. Oh, I just double check sabre23t don’t have that many edits. At least now I see there are quite a few active editors in Malaysia. 
There are many questionable boundaries. Some that I recall:
- residential area boundaries in Selangor. Some of these were added by university students during one of those mapathon sessions. They follow google maps version very closely (no wonder:( )
- district boundaries. This is derived from the so called Sinar Project. Sinar Project put these boundaries out after tracing (!) them from some other maps.
- PBT boundaries. These somehow are incorporated as administration boundary, which ended up as address in Nominatim search. For example, an address will become: No 5, Persiaran Satu, Tmn Bestari Perdana, Bestari Jaya, Majlis Daerah Hulu Selangor, Selangor, Malaysia.
The first issue is now ignored since those mappers were just doing one day wonders - most didn’t bother to reply their emails.
The second and third issue is more problematic since it is done by someone who is pretty active in mapping but is not strictly bound to OSM guidelines, despite being told so.
Just so you’d know. People are still going for the completeness approach without bothering with the legalities approach.
~ menyesal dahulu pendapatan, menyesal kemudian tidak berguna ~
Search “Bandar Bestari” finds two features:
1/ Point/Node/Neighbourhood that is at the right place.
2/ Area/Way/Residential that is at the wrong place (near Aeon Bukit Tinggi).
I got stuck finding a way to move an Area in iD. I couldn’t see how. Hah. I need to go http://learnosm.org/en/beginner/id-editor/ first. 
Select the desired element (which is the area or closed way of Bandar Bestari). Right-click it, move it, and then press Enter. However, see this video first.
Some of its points are shared between the adjacent highways, etc.
See the steps how to untangle them.
The context menu can be accessed by right-click.
You can save some time with keyboard shortcuts!
Oops, I missed your advice @AkuAnakTimur. I have just uploaded the changeset and solved my problems as below …
1/ I needed to right-click on the erroneous Residential Area at the right place. Click on the edges, not on the nodes. Then context menu to Move it is available.
2/ I solved the tangled/shared nodes by doing a Rotation of that Residential Area first, before doing the above Move.
3/ I’ve set the area boundaries to cover the main area already developed, it need to be expanded later to adjacent areas of Bandar Bestari that’s being developed or not yet developed.
Anyway, I hope you can have a look and comment on the changeset. I just had a look at the videos you linked, thanks. Next time I should just PM or WA you first. Hehe.