Major updates come in the form of an integer change on the version number (any number to the left of the decimal). Ex. 248.xx -> 249.xx
Majors will require both client and server to update, ASAP, to ensure proper connectivity, and server availability within the server list.
Minor updates come in the form of a fractional change on the version number (any number to the right of the decimal. Ex 248.50 -> 248.60
MOST minor updates will NOT require the server to update, to maintain connectivity and availability within the server list. There are rare exceptions, which Stuido WildCard will mention within the minor change notes.
Mods are handled somewhat similar, only that the 'version number' is stored in the mod's GUID. Every time the Mod GUID changes, it is considered a 'major' update. Mod GUID != Publisher ID (Mod ID)
Mods that update and reset Mod GUID will force servers to update to be visible within the server list again. This will also ensure all servers will be running the most recent version of the mod before they can continue using it. Clients that can see the server, that have the update mod, when they try to connect, will be presented with a Mod mismatch error.
Mods that change server-side code, that do not reset Mod GUID, are likely to have clients crash or timeout when they encounter an item from that mod. This is the main use for resetting Mod GUID.
Modders that have changed server-side code within their mod, should reset the Mod GUID before cooking and uploading. Mod GUID MUST be reset BEFORE cooking the mod!