wMaxVersion

wMaxVersion is a term used in software systems to denote the maximum version of a protocol, interface, or feature set that a component can support. It is not a universal standard; its exact meaning is defined by the project or protocol in which it appears. Typically, wMaxVersion appears as a field in handshake messages, configuration data, or capability advertisements that participate in version or feature negotiation between two parties, such as a client and server or a device and driver.

In such negotiations, wMaxVersion is used to determine a compatible version range. It is often paired with a corresponding minimum version or with a list of supported versions. The negotiated version is typically the lesser of the peer’s wMaxVersion and the other side’s declared maximum, ensuring backward compatibility.

Formats vary: it may be a numeric value, a dotted string like 2.1, or a semantic version. Some implementations treat it as an integer index into a protocol version catalog. The choice of representation affects parsing and compatibility checks.

Examples: In a custom RPC protocol, a client sets wMaxVersion to 3; the server matches with a supported version and communicates down at 2. In device firmware, wMaxVersion may indicate the maximum protocol revision the device can handle.

Limitations: Exposing a maximum version does not guarantee support for all features at that version; feature availability depends on implementation. Changes to wMaxVersion usually require coordinated updates across communicating components.