SOLAS VGM (Verified Gross Mass) is effective as from 1ste of July 2016.
VGM is required for containers shipped by sea.
TCI Carriers about SOLAS – VGM
TCI Carriers designed a clear overview about SOLAS – VGM : PDF TCI CARRIERS
Method 1 and method 2
In search of more information about method 1 and method 2 : open this PDF.
Extended information
Looking for extended information SOLAS mandatory requirement.