Cargo Features

[dependencies]
tellem = { version = "0.2.0", default-features = false, features = ["codec"] }
default = codec

The codec feature is set by default whenever tellem is added without default-features = false somewhere in the dependency tree.

codec default = tokio-util

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

tokio-util codec