docs: clarify omitted slot vs empty slot in $$slots

site/content/docs/02-template-syntax.md

@@ -1291,7 +1291,7 @@ Named slots allow consumers to target specific areas. They can also have fallbac
 
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-`$$slots` is an object whose keys are the names of the slots passed into the component by the parent. If the parent leaves a named slot empty, `$$slots` will not have a key for that slot. This allows components to render a slot (and other elements, like wrappers for styling) only if the parent provides children for it.
+`$$slots` is an object whose keys are the names of the slots passed into the component by the parent. If the parent does not pass in a slot with a particular name, that name will not be a present in `$$slots`. This allows components to render a slot (and other elements, like wrappers for styling) only if the parent provides it.
 
 ```sv
 <!-- App.svelte -->
@@ -1310,6 +1310,8 @@ Named slots allow consumers to target specific areas. They can also have fallbac
 </div>
 ```
 
+Note that explicitly passing in an empty named slot will add that slot's name to `$$slots`. For example, if a parent passes `<div slot="title" />` to a child component, `$$slots.title` will be truthy within the child.
+
 #### [`<slot let:`*name*`={`*value*`}>`](slot_let)
 
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