diff --git a/docs/doc/hefquin_service.html b/docs/doc/hefquin_service.html
index 2e5fe4110b..d6b2b95773 100644
--- a/docs/doc/hefquin_service.html
+++ b/docs/doc/hefquin_service.html
@@ -98,50 +98,51 @@ <h2>Issuing Queries</h2>
             <p>
                 Furthermore, the client may include any of the following headers to control the query processing or to
                 request additional information about the query and its execution. The headers that request additional
-                information in the response are only supported if the response format is JSON.
+                information in the response are only supported if the response format is JSON. Each header accepts the
+                value <code>true</code> or <code>false</code>. The default value is <code>false</code>.
             </p>
             <ul>
-                <li><code>X-HeFQUIN-Skip-Execution</code> - Use this argument if you want HeFQUIN to create the query
+                <li id="X-HeFQUIN-Skip-Execution"><code>X-HeFQUIN-Skip-Execution</code> - Use this header if you want HeFQUIN to create the query
                     execution plan for the given query, but without actually executing this plan.</li>
-                <li><code>X-HeFQUIN-Print-Source-Assignment</code> - Use this argument to instruct the query planning
+                <li id="X-HeFQUIN-Print-Source-Assignment"><code>X-HeFQUIN-Print-Source-Assignment</code> - Use this header to instruct the query planning
                     component of HeFQUIN to include the initial logical plan that is the output of the source selection
                     &amp; query decomposition process in the response; i.e., this is the logical plan that is passed as
                     input to the logical query optimizer.
                     To include the plan in the JSON response, it is represented as a single (multi-line) string that is
                     given as value for a key named <code>sourceAssignment</code>.
-                <li><code>X-HeFQUIN-Print-Logical-Plan</code> - Use this argument to instruct the query planning
+                <li id="X-HeFQUIN-Print-Logical-Plan"><code>X-HeFQUIN-Print-Logical-Plan</code> - Use this header to instruct the query planning
                     component of HeFQUIN to include the logical plan that is the output of the logical query optimizer
                     in the response; i.e., this is the logical plan that is passed as input to the physical query
                     optimizer. To include the plan in the JSON response, it is represented as a single (multi-line) string
                     that is given as a value for a key named <code>logicalPlan</code>.
-                <li><code>X-HeFQUIN-Print-Physical-Plan</code> - Use this argument to instruct the query planning
+                <li id="X-HeFQUIN-Print-Physical-Plan"><code>X-HeFQUIN-Print-Physical-Plan</code> - Use this header to instruct the query planning
                     component of HeFQUIN to include the physical plan that is the output of the physical query optimizer
                     in the response; i.e., this is the physical plan that is used to execute the query. To include the plan
                     in the JSON response, it is represented as a single (multi-line) string that is given as a value for a
                     key named <code>physicalPlan</code>.
-                <li><code>X-HeFQUIN-Print-Executable-Plan</code> - Use this argument to instruct the query planning
+                <li id="X-HeFQUIN-Print-Executable-Plan"><code>X-HeFQUIN-Print-Executable-Plan</code> - Use this header to instruct the query planning
                     component of HeFQUIN to include the executable plan produced by the query planning component in the
                     response; i.e., this is the plan consisting of the concrete executable operators that are used to
                     execute the query. To include the plan in the JSON response, it is represented as a single (multi-line)
                     string that is given as a value for a key named <code>executablePlan</code>.
-                <li><code>X-HeFQUIN-Return-Query-Proc-Stats</code> - Use this argument to instruct the HeFQUIN engine
+                <li id="X-HeFQUIN-Return-Query-Proc-Stats"><code>X-HeFQUIN-Return-Query-Proc-Stats</code> - Use this header to instruct the HeFQUIN engine
                     to include detailed statistics about the query planning and the query execution processes, as
                     collected by the different components involved in these processes (including the operators that
                     have been part of the query execution plan), in the response. To include the statistics in the JSON
                     response, they are represented as a JSON object that is given as a value for a key named
                     <code>queryProcStats</code>.</li>
-                <li><code>X-HeFQUIN-Return-Fed-Access-Stats</code> - Use this argument to instruct the HeFQUIN engine
+                <li id="X-HeFQUIN-Return-Fed-Access-Stats"><code>X-HeFQUIN-Return-Fed-Access-Stats</code> - Use this header to instruct the HeFQUIN engine
                     to include detailed statistics collected by the federation access component of HeFQUIN in the
                     response. To include the statistics in the JSON response, they are represented as a JSON object that
                     is given as a value for a key named<code>fedAccessStats</code>.</li>
-                <li><code>X-HeFQUIN-Return-Full-Stack-Trace</code> - Use this argument to instruct the HeFQUIN engine
+                <li id="X-HeFQUIN-Return-Full-Stack-Trace"><code>X-HeFQUIN-Return-Full-Stack-Trace</code> - Use this header to instruct the HeFQUIN engine
                     to include the complete stack trace for each exception, in addition to the exception message,
                     in the <code>exceptions</code> field of the JSON response.</li>
-                <li><code>X-HeFQUIN-Ignore-Retrieval-Cache</code> - Use this argument to instruct the HeFQUIN engine
+                <li id="X-HeFQUIN-Ignore-Retrieval-Cache"><code>X-HeFQUIN-Ignore-Retrieval-Cache</code> - Use this header to instruct the HeFQUIN engine
                     to bypass the retrieval cache when processing the query, which means that every data retrieval request
                     during every execution is indeed executed instead of being served from the cache. The responses received
                     for these requests are still used to update the cache.</li>
-                <li><code>X-HeFQUIN-Ignore-Cardinality-Cache</code> - Use this argument to instruct the HeFQUIN engine
+                <li id="X-HeFQUIN-Ignore-Cardinality-Cache"><code>X-HeFQUIN-Ignore-Cardinality-Cache</code> - Use this header to instruct the HeFQUIN engine
                     to bypass the cardinality cache when processing the query, which means that cardinality requests are
                     indeed issued instead of being served from the cache.
                     The responses obtained via such requests are still used to update the cache.</li>