Source

File: wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php

protected function get_schema_links() {

		$href = rest_url( "{$this->namespace}/{$this->rest_base}/{id}" );

		$links = array();

		if ( 'attachment' !== $this->post_type ) {
			$links[] = array(
				'rel'          => 'https://api.w.org/action-publish',
				'title'        => __( 'The current user can publish this post.' ),
				'href'         => $href,
				'targetSchema' => array(
					'type'       => 'object',
					'properties' => array(
						'status' => array(
							'type' => 'string',
							'enum' => array( 'publish', 'future' ),
						),
					),
				),
			);
		}

		$links[] = array(
			'rel'          => 'https://api.w.org/action-unfiltered-html',
			'title'        => __( 'The current user can post unfiltered HTML markup and JavaScript.' ),
			'href'         => $href,
			'targetSchema' => array(
				'type'       => 'object',
				'properties' => array(
					'content' => array(
						'raw' => array(
							'type' => 'string',
						),
					),
				),
			),
		);

		if ( 'post' === $this->post_type ) {
			$links[] = array(
				'rel'          => 'https://api.w.org/action-sticky',
				'title'        => __( 'The current user can sticky this post.' ),
				'href'         => $href,
				'targetSchema' => array(
					'type'       => 'object',
					'properties' => array(
						'sticky' => array(
							'type' => 'boolean',
						),
					),
				),
			);
		}

		if ( post_type_supports( $this->post_type, 'author' ) ) {
			$links[] = array(
				'rel'          => 'https://api.w.org/action-assign-author',
				'title'        => __( 'The current user can change the author on this post.' ),
				'href'         => $href,
				'targetSchema' => array(
					'type'       => 'object',
					'properties' => array(
						'author' => array(
							'type' => 'integer',
						),
					),
				),
			);
		}

		$taxonomies = wp_list_filter( get_object_taxonomies( $this->post_type, 'objects' ), array( 'show_in_rest' => true ) );

		foreach ( $taxonomies as $tax ) {
			$tax_base = ! empty( $tax->rest_base ) ? $tax->rest_base : $tax->name;

			/* translators: %s: Taxonomy name. */
			$assign_title = sprintf( __( 'The current user can assign terms in the %s taxonomy.' ), $tax->name );
			/* translators: %s: Taxonomy name. */
			$create_title = sprintf( __( 'The current user can create terms in the %s taxonomy.' ), $tax->name );

			$links[] = array(
				'rel'          => 'https://api.w.org/action-assign-' . $tax_base,
				'title'        => $assign_title,
				'href'         => $href,
				'targetSchema' => array(
					'type'       => 'object',
					'properties' => array(
						$tax_base => array(
							'type'  => 'array',
							'items' => array(
								'type' => 'integer',
							),
						),
					),
				),
			);

			$links[] = array(
				'rel'          => 'https://api.w.org/action-create-' . $tax_base,
				'title'        => $create_title,
				'href'         => $href,
				'targetSchema' => array(
					'type'       => 'object',
					'properties' => array(
						$tax_base => array(
							'type'  => 'array',
							'items' => array(
								'type' => 'integer',
							),
						),
					),
				),
			);
		}

		return $links;
	}