StartDTD

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

Starts a DTD

public function startDTD(
  string $qualifiedname,
  string $publicid = NULL,
  string $systemid = NULL,
): bool;

Parameters

• string $qualifiedname - The qualified name of the document type to create.
• string $publicid = NULL - The external subset public identifier.
• string $systemid = NULL - The external subset system identifier.

Returns

• bool - - Returns TRUE on success or FALSE on failure.