In its simplest form, a search expression just contains a string to be searched for with the help of a full-text search.
For example, the string `syntax` will search for all zettel containing the word “syntax”.

If you want to search for all zettel with a title containing the word “syntax”, you must specify `title:syntax`.
“title” denotes the [metadata key](00001006010000), in this case the [supported metadata key “title”](00001006020000#title).
The colon character (“`:`”) is a [search operator](00001007705000), in this example to specify a match.
“syntax” is the [search value](00001007706000) that must match to the value of the given metadata key, here “title”.

A search expression may contain more than one search term, such as `title:syntax`.
Search terms must be separated by one or more space characters, for example `title:syntax title:search`.
All terms of a select expression must be true so that a zettel is selected.

Above sequence of search expressions may be combined by specifying the keyword `OR`.
At most one of those sequences must be true so that a zettel is selected.

* [Search term](00001007702000)
* [Search operator](00001007705000)
* [Search value](00001007706000)