Extension points

Extend AbstractExtension and override only the contracts owned by the extension.

Method	Contribution	Execution point
`directives()`	`DirectiveSpec`	Parsing and profile checks
`roles()`	`RoleSpec`	Inline parsing and profile checks
`directiveHandlers()`	`DirectiveHandler`	HTML and Markdown conversion
`roleHandlers()`	`RoleHandler`	HTML and Markdown conversion
`lintRules()`	lint rule	Linting with the active profile
`fixPasses()`	`FixPass`	Safe fixing
`formatterPasses()`	`FormatterPass`	Formatting under the parse guard
`statisticsProviders()`	`StatisticsProvider`	Namespaced document metrics

<?php
$extended = $profile->withExtension($extension);

The returned profile is new. Later extensions replace handlers, passes, rules, or providers with the same normalized name.

Directive body kinds declare whether content is parsed as blocks, preserved as literal data, retained as opaque syntax, or forbidden. Choose the exact model so references are neither invented inside code nor hidden inside ordinary RST.

See Custom extension for registration and Security for authority boundaries.