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    :caption: Contents:
 
    cli
+   query-language
 
 Reference Documentation
 -----------------------
diff --git a/docs/query-language.rst b/docs/query-language.rst
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+Search Query Language
+=====================
+
+
+Every query is composed of filters separated by ``&&`` or ``||``
+which represent AND and OR respectively. These filters have
+3 components in the order : ``Name Operator Value``
+
+**Note:** Whitespaces are optional between the three components of a filter.
+
+Some of the examples are :
+    * ``origin = django && language in [python] && visits >= 5``
+    * ``last_revision > 2020-01-01 limit = 10``
+    * ``last_visit > 2021-01-01 || last_visit < 2020-01-01``
+    * ``visited = false && metadata = "gitlab"``
+    * ``keyword in ["orchestration", "kubectl"] && language in [go, rust]``
+    * ``visit_type = [deb] && license in ["GPL-3"]``
+
+
+The filters have been classfied based on the type of the value that it expects.
+
+
+Pattern filters
+---------------
+
+    * Name: ``origin`` ``metadata``
+    * Operator: ``=``
+    * Value: String wrapped in quotation marks(``"`` or ``'``)
+
+**Note:** If the string has no whitespace then the quotation marks become optional.
+
+**Examples:**
+
+    * ``origin = https://github.com/Django/django``
+    * ``origin = kubernetes``
+    * ``origin = "github python"``
+    * ``metadata = orchestration``
+    * ``metadata = "javascript language"``
+
+Boolean filters
+---------------
+
+
+    * Name: ``visited``
+    * Operator: ``=``
+    * Value: ``true`` or ``false``
+
+**Examples:**
+
+    * ``visited = true``
+    * ``visited = false``
+
+
+Numeric filters
+---------------
+
+    * Name: ``visits``
+    * Operator: ``<`` ``<=`` ``=`` ``!=`` ``>`` ``>=``
+    * Value: Positive integer
+
+**Examples:**
+
+
+    * ``visits > 2``
+    * ``visits = 5``
+    * ``visits <= 10``
+
+
+Un-bounded List filters
+-----------------------
+
+Returns origins that satisfy the criteria based on a given list
+
+    * Name:
+        * ``language`` : Programming languages used
+        * ``license`` : License used
+        * ``keyword`` : Keywords(tags) + Description(includes README) of the repository
+    * Operator: ``in`` ``not in``
+    * Value: Array of strings
+
+**Note:** If string has no whitespace then the quotation marks become optional.
+
+**Examples:**
+
+    * ``language in [python, js]``
+    * ``license in ["GPL 3.0 or later", MIT]``
+    * ``keyword in ["Software Heritage", swh]``
+
+
+Bounded List filters
+--------------------
+
+Returns origins that satisfy the criteria based on a list of fixed options
+
+    **visit_type**
+
+    * Name: ``visit_type`` : Returns only origins with at least one of the specified visit types
+    * Operator: ``=``
+    * Value: Array of the following values
+
+        ``any``
+        ``cran``
+        ``deb``
+        ``deposit``
+        ``ftp``
+        ``hg``
+        ``git``
+        ``nixguix``
+        ``npm``
+        ``pypi``
+        ``svn``
+        ``tar``
+
+    **sort_by**
+
+    * Name: ``sort_by`` : Sorts origins based on the given list of origin attributes
+    * Operator: ``=``
+    * Value: Array of the following values
+
+        ``visits``
+        ``last_visit``
+        ``last_eventful_visit``
+        ``last_revision``
+        ``last_release``
+        ``created``
+        ``modified``
+        ``published``
+
+**Examples:**
+
+
+    * ``visit_type = [svn, npm]``
+    * ``visit_type = [nixguix, "ftp"]``
+    * ``sort_by = ["last_visit", created]``
+    * ``sort_by = [visits, modified]``
+
+Date filters
+------------
+
+Returns origins having their date type values in the given range
+
+    * Name:
+
+            * ``last_visit`` : Latest visit date
+            * ``last_eventful_visit`` : Latest visit date when a new snapshot was detected
+            * ``last_revision`` : Latest commit date
+            * ``last_release`` : Latest release date
+            * ``created`` Creation date
+            * ``modified`` Modification date
+            * ``published`` Published date
+
+    * Operator: ``<`` ``<=`` ``=`` ``!=`` ``>`` ``>=``
+    * Value: Date in ``Standard ISO`` format
+
+    **Note:** Last three date filters are based on metadata which has to be manually entered
+    by the repository authors and hence it might not be correct or up-to-date.
+
+**Examples:**
+
+    * ``last_visit > 2001-01-01 && last_visit < 2101-01-01``
+    * ``last_revision = "2000-01-01 18:35Z"``
+    * ``last_release != "2021-07-17T18:35:00Z"``
+    * ``created <= "2021-07-17 18:35"``
+
+Limit filter
+------------
+
+Limits the number of results to at most N
+
+    * Name: ``limit``
+    * Operator: ``=``
+    * Value: Positive Integer
+
+**Examples:**
+
+    * ``limit = 1``
+    * ``limit = 15``