In LiteFlow EL rules, you can also write comments. There are 2 ways to write comments:

single line comment

<chain name="chain1">
    //I am a comment
    THEN(a, b, WHEN(c, d))
</chain>

multi-line comment

<chain name="chain1">
    THEN(
        //I am a comment
        a, 
        b, 
        /**
        * I am multi-line comments
        * I am multi-line comments
        **/
        WHEN(c, d)
    )
</chain>