Information that can be edited here depends on whether the item is linked to an article or not.
Meter [Virtual]: This is used when meter readings for an asset need to be accumulated to a connected item. Also supports control of counters from other objects.
If the item is connected to an article, these fields will be locked to prevent editing, since the values in these are taken from the article card:
Article
Serial number
Group
Type
Supplier
Manufacturer
Any other extra information from the article group
+ Document: Documents can be uploaded to the item.