``block`` ========= Blocks are used for inheritance and act as placeholders and replacements at the same time. They are documented in detail in the documentation for the :doc:`extends<../tags/extends>` tag. Block names should consist of alphanumeric characters, and underscores. Dashes are not permitted. .. seealso:: :doc:`block<../functions/block>`, :doc:`parent<../functions/parent>`, :doc:`use<../tags/use>`, :doc:`extends<../tags/extends>`