What is an include area?

Question

1C-Bitrix

Is it possible to include a separate file only for the main page, but include it in the header? Those. for the whole template, but to display it only on the main one?
In order not to make several templates - for the main and internal pages

Answer 1

<? if(CSite::InDir('/index.php')) :?>
  сюда включаемая область
<? endif; ?>

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edited