```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/">
    <query_name>Medications@13:56:27</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <panel>
        <panel_number>1</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>1</hlevel>
            <item_name>Medications</item_name>
            <item_key>\\i2b2_MEDS\i2b2\Medications\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Medications</tooltip>
            <class>ENC</class>
            <constrain_by_modifier>
                <modifier_name>Rx Sig</modifier_name>
                <modifier_key>\\i2b2_MEDS\Medication\RxSig\</modifier_key>
                <applied_path>\i2b2\Medications\%</applied_path>
                <constrain_by_value>
                    <value_operator>EQ</value_operator>
                    <value_constraint>@</value_constraint>
                    <value_type>FLAG</value_type>
                </constrain_by_value>
            </constrain_by_modifier>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
</ns4:query_definition>

```

I want to find all medications that have been prescribed to patients within the i2b2 database, regardless of the timing or specificity, and display the results on a single panel with a high accuracy scale of 100, and the class type is ENC (Encounter). The query will be constrained by the modifier "Rx Sig" and the value constraint will be equal to the flag symbol "@". The query will not include synonyms.