Single-line Comments

Single-line comments start with two forward slashes (//).
Any text between // and the end of the line is ignored (will not be executed).

This example uses a single-line comment before a line of code:

shell
{
    dynamic 
    {
        // This is a comment
        item(title='Hello World!')
        
        //item(title='Hello World!')
    }
}

This example uses a single-line comment at the end of a line of code:

shell
{
    dynamic 
    {
        item(title='Hello World!') // This is a comment
    }
}

Multi-line Comments

Multi-line comments start with /* and ends with */.
Any text between /* and */ will be ignored.

shell
{
    dynamic
    {
        item(title='Hello,/* multiple-lines comment inside */ world')
        
        /*
        item(title='test item 1')
        item(title='test item 2')
        */
    }

}

Single or multi-line comments?
It is up to you which you want to use. Normally, we use // for short comments, and /* */ for longer.