E404

E404 is a designation used in multiple, unrelated contexts to label a specific item, code, or route. It does not refer to a single universally defined entity, but rather to different concepts depending on the domain.

In computing and information technology, E404 is commonly used as an error code label to indicate a not found condition—signifying that a requested resource could not be located. While this mirrors the meaning of the HTTP 404 status in web contexts, E404 as a log or diagnostic code may be used by different software, embedded systems, or service backends. The exact meaning of E404 can vary by vendor, platform, or programming language, and is typically clarified by accompanying messages or subsystem documentation.

In transportation, E404 can refer to a European road designation within the international E-road network. The E404 label marks a specific route across participating European states. The precise alignment, length, and endpoints of E404 are defined by international agreements and national implementations, and may be adjusted over time.

E404 also appears as a model or catalog identifier in various industries, including consumer electronics, automotive parts, or industrial equipment. As with other codes, its interpretation depends on the context in which it is used, and locating the relevant documentation or database entry is necessary for an exact definition.

Because E404 spans multiple domains, identifying the domain and consulting the corresponding specifications is essential to determine its precise meaning in any given instance.