Have a look at this resolution of Maritime safety committee of the IMO.

This is the resolution number MSC.192 (79). The sequence number of the resolution is 192. The resolution was passed by the MSC (Maritime safety committee) of IMO. That is what MSC denotes in the resolution number.

The number 79 in the brackets signifies that this resolution was adopted in 79th session of the maritime safety committee.

I am sure that will make clear about other resolutions mentioned in the above picture.

For example Resolution A.886(21) means that this resolution was passed by the Assembly in its 21st Session and the resolution number is 886.