Terms

This page defines the terminology used throughout the Validation Rules specification (ELCL-VR). The terms introduced here are used consistently in all following chapters and are essential for understanding both the rules themselves and the requirements placed on validators.

Vocabulary

Validation Rules use the following core terms:

  • Node — a single location in the value tree that may be validated. A node can represent a value, a section, or a list.

  • Node-Rules — the complete set of constraints and metadata that apply to a specific node.

  • Name Path — the normalized path that uniquely identifies a node within the value tree.

  • Section — a structured node containing named child entries, usually with regular names unless noted otherwise.

  • Section List — a node containing multiple sections that all share the same name.

  • Value List — a node containing an ordered sequence of scalar values.

  • Reserved Name — a predefined identifier in a validation rules document with special meaning, always starting with the prefix vr_.

Examples

Throughout this specification, examples are rendered using visually distinct box styles. These styles help you immediately understand what kind of document you are looking at and how it relates to the validation rules.

The following examples demonstrate all box styles used in this chapter.

Validation Rule Documents

Validation rule documents define constraints and checks that are applied to configuration files.

# This is a valid validation rules document.
# It follows the rules defined in this specification.

# This validation rules document does not conform
# to the requirements of this specification.

Configuration Examples

Configuration examples show how real-world configuration documents behave when they are validated against a set of rules.

# This configuration document conforms to
# the associated validation rules.

# This configuration document violates
# one or more validation rules.

Identifier Normalization

Identifiers given as text in Validation Rules are case-insensitive and follow the same normalization rules as names in ELCL. For comparison purposes, underscores (_) and spaces are treated as equivalent.

For simplicity and consistency, all examples in this specification use normalized identifiers. In real-world documents, however, it can be helpful to take advantage of normalization for readability, for example by writing VR any instead of vr_any.

See Name Normalization for a detailed description of name normalization rules.

Reserved Names

All reserved names begin with the prefix vr_. They have predefined semantics in Validation Rules and must not be redefined or used for regular configuration entries.

See Reserved Names for the complete list of reserved names and their meanings.

Conformance Language

This specification uses simple and consistent language to express normative requirements:

  • The word must indicates an absolute requirement for conformance.

  • The word should indicates a recommended feature that is optional but strongly encouraged.

  • The word may indicates an optional feature.

If an element is described as must be present or supported, a parser that omits it does not conform to this specification. Elements described with should are optional but recommended, while may marks features that can be freely omitted without breaking conformance.