I created a Custom Attribute at the Infrastructure Services Container with no value, and made it inheritable.  
I then set a value on a node (about 3 containers down). 

When I delete the Custom Attribute at the Infrastructure Services Container level, the VALUE of custom attribute on the node is deleted, but the Custom Attribute itself is still there.  

I would have expected:
A)  Deleting a custom attribute would remove it and the value from all child objects.
or
B)  Deleting a custom attribute would remove it from all child objects that have not been defined with a different value.

I would prefer  "B"..... If a custom attribute is removed, I would appreciate it, if it did not delete all values on child objects which are different than the value being deleted (i.e. if something is defined or has a override at a child object DONT delete it).    This could easily wipe out hundreds or thousands of custom defined values which could be nearly impossible to repair.  

But the current behavior I saw (I tested it a few times, a few different ways) was completely unexpected and not what I assume the intention was/is. 

As a side note feature request, there are a number of things in NetXMS which it will catastrophically let you do without warning.   More than once I have accidentally chosen a "delete" option on something, thinking I was removing it from a template, container, etc only to have NetXMS completely deleted the Node.  I realize this is ultimately my fault but sometimes those late 3-4am nights get the best of me and I click without completely processing what is about to happen haha. 

Thanks!