Is it safe to delete old Javascript code?

Hi all,

I'm using RH 2020.7.46 working with an inherited project, which has been upgraded several times from older versions of RH over the years. I've noticed there are some pages which have an old script at the end of the code before the </body> tag

  <script type="text/javascript" language="JavaScript1.2">
    //<![CDATA[
    if (typeof(InitEffects) != 'function') InitEffects = new Function();
    InitEffects('h21');
    InitEffects('h22');
    InitEffects('h23');
    InitEffects('h24');
    InitEffects('h25');
    InitEffects('h26');
    InitEffects('h27');
    //]]>
  </script>

 I'm not entirely sure what this code does, or why it's only on some of the pages. I'm cleaning up some of the HTML which has inherited lots of extra code along the way, including text formatting and external links rather than project links, just because of the way the data has been handled in the past. 

Can anyone tell me what this script is for, and if I can remove it?

Thanks,

Mikey 🙂