LIKE expressions are of the form:
        identifier [NOT] LIKE pattern-value [ESCAPE escape-character] 
      where identifier has a String value; pattern-value is a string literal
      where '_' stands for any single character; '%' stands for any sequence of
      characters, including the empty sequence, and all other characters stand 
      for themselves. The optional escape-character is a single-character 
      string literal whose character is used to escape the special meaning of 
      the '_' and '%' in pattern-value.
    
See:
- 
            Section 3.8.1.1,
            Message Selector Syntax