Thanks for the reply Alberto.

I had looked at typed collections (there is a code snippet for that, at
least), but I still need to overload the Add in a majority of cases so that I
can do additional processing before adding the class to the collection (or
not adding it, if the validation checking fails).

In this case I wouldn't be able to use a Generic collection, right?

At the moment, for example, I have a Task class that exposes various
properties, methods and functions for handling numerous tasks.

The Tasks class looks something like this:
   public class Tasks : CollectionBase
   {
       ...
       public boolean Add ( Task pTaskToAdd )
       {
           // Do task specific checks and processing, return false if error

           List.Add ( pTaskToAdd );

           return true;
       }
   }

And used in the TaskHandler class like this:

   static Tasks queuedTasks;

   Task printTask = new Task(printJobID, printPrinter);
   
   if ( queuedTasks.Add(printTask) )
         // Task queued successfully
   else
         // Task failed to be added to task queue

If I use the generic collections, it would be something like this -

   static List<Task> queuedTasks;

But I don't know how I would replace the Add method with my own.