Simple Callback to customize the 50 user limit in owner dropdowns==
Creating the Callback
Under "rt4/local/html", if you haven't already, create a directory called "Callbacks" (careful with the case).
Under your new "rt4/local/html/Callbacks" directory, create a directory named anything you like (mine is GHCITS) - This is just to help organize your callbacks.
Next, under the folder that you just created (in my case "/rt4/local/html/Callbacks/GHCITS") you will need to replicate the path to the callback we will be modifying. The callback we are trying to intercept lives in "/rt4/share/html/Elements/SelectOwnerDropdown", so we need to make this structure exist under our new callback tree. You do not have to include the "html" directory. So, using my case as an example, I created:
Finally, inside the SelectOwnerDropdown directory, you will need to create a file called "ModifyDropdownLimit" (this is the name of the actual callback) that contains:
<%INIT> $$DropdownLimit = 150; <%ARGS> $DropdownLimit => undef
This will set the new dropdown limit to 150 (set it to whatever you wish). This will cause a performance hit, but in my case it was slight.