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<concept xml:lang="en" id="GUID-E0DC9706-AAC5-5950-86E8-D667A7AFCD49"><title>Reserved and Unreserved Characters </title><prolog><metadata><keywords/></metadata></prolog><conbody><p>This section explains the concept of reserved, unsafe and unreserved characters. </p> <section id="GUID-B5EB7F55-60AF-5703-96F6-0C42A3D433EE"><title>Reserved characters</title> <p>URIs use some characters for special purposes in defining their syntax, these are called reserved characters. For example, - ; / ? : &amp; = . When these characters are not used in their special role inside a URI, they need to be encoded. </p> <p>The following lists the reserved characters for different URI components as defined in <xref href="GUID-0B61C1D3-7DAB-3149-932F-1F96A84EDF42.dita"><apiname>TEscapeMode</apiname></xref>: </p> <table id="GUID-3DC3AB61-1F62-59BE-B6ED-2299B1B72B3B"><tgroup cols="3"><colspec colname="col0"/><colspec colname="col1"/><colspec colname="col2"/><thead><row><entry>Escape Mode</entry> <entry>URI component</entry> <entry>Reserved Characters </entry> </row> </thead> <tbody><row><entry><p>EscapeNormal </p> </entry> <entry><p>None </p> </entry> <entry><p>No reserved characters </p> </entry> </row> <row><entry><p>EscapeQuery </p> </entry> <entry><p>query </p> </entry> <entry><p>- ;/?:&amp;=+$,[] </p> </entry> </row> <row><entry><p>EscapePath </p> </entry> <entry><p>path </p> </entry> <entry><p>- /;=?[] </p> </entry> </row> <row><entry><p>EscapeAuth </p> </entry> <entry><p>authority </p> </entry> <entry><p>- /;:@?[] </p> </entry> </row> <row><entry><p>EscapeUrlEncoded </p> </entry> <entry><p>URL </p> </entry> <entry><p>;/?:&amp;=+$[]!\'()~ </p> </entry> </row> </tbody> </tgroup> </table> </section> <section><title>Unsafe characters </title> <p>Some characters present the possibility of being misunderstood within URIs for various reasons. These are called unsafe characters and must always be encoded. For example, '#' character is used in URIs to indicate where a fragment identifier (bookmarks/anchors in HTML) begins. </p> </section> <section><title> Unreserved characters</title> <p>Data characters that are allowed in a URI but do not have a reserved purpose are called "unreserved" characters. These include upper and lower case letters, decimal digits, a limited set of punctuation marks and symbols, ASCII control characters which are not printable. For example, the ISO-8859-1 (ISO-Latin) character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal). </p> <p> <xref href="GUID-6BD89347-671F-3518-9777-55801A090C79.dita"><apiname> </apiname></xref>  <xref href="GUID-9CC256C4-D4A2-3534-9B3C-2FBF1AAE5F51.dita"><apiname>EscapeUtils</apiname></xref> escape encodes and decodes unsafe data in URI. It also supports converting of Unicode data (16-bit descriptor) into UTF8 data (8-bit descriptor) and vice-versa. <xref href="GUID-6BD89347-671F-3518-9777-55801A090C79.dita"><apiname/></xref>  </p> <p> <xref href="GUID-9CC256C4-D4A2-3534-9B3C-2FBF1AAE5F51.dita"><apiname>EscapeUtils</apiname></xref> provides the following functionality. </p> </section> </conbody><related-links><link href="GUID-795B41AF-FBEA-56CE-AE20-EF17BE754723.dita"><linktext>HTTP Utilities Library Overview</linktext> </link> <link href="GUID-0E8206E9-4F1D-5DF5-8A69-9B0831061CFF.dita"><linktext>Escape encoding and decoding

                tutorial</linktext> </link> <link href="GUID-853BFDC0-1993-5EFC-AA68-C9EA496EEF3F.dita"><linktext>Converting between Unicode and