```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>Patient Instruc@20:47:31</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>6</hlevel>
            <item_name>Maxair Autohaler 0.2 mg/inh aerosol with adapter 3 M Pharmaceuticals</item_name>
            <item_key>\\i2b2_MEDS\i2b2\Medications\MUL\(LME219) respiratory agents\(LME223) bronchodilators\(LME224) adrenergic bronchodilators\pirbuterol\00089081710\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>medications \ respiratory agents \ bronchodilators \ adrenergic bronchodilators \ pirbuterol \ maxair autohaler 0.2 mg/inh aerosol with adapter 3 m pharmaceuticals</tooltip>
            <class>ENC</class>
            <constrain_by_modifier>
                <modifier_name>Patient Instructions</modifier_name>
                <modifier_key>\\i2b2_MEDS\Medication\Instructions\</modifier_key>
                <applied_path>\i2b2\Medications\%</applied_path>
                <constrain_by_value>
                    <value_operator>CONTAINS</value_operator>
                    <value_constraint>e</value_constraint>
                    <value_type>LARGETEXT</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 instances where the medication Maxair Autohaler 0.2 mg/inh aerosol with adapter 3 has been prescribed to patients and the patient instructions contain the letter 'e'. The query will be applied to the medications panel, with a specificity scale of 0 and accuracy scale of 100. The timing is set to ANY, meaning it does not matter when the medication was prescribed. The query will look for the presence of the letter 'e' within the patient instructions for this medication using the constrain_by_modifier parameter.