Creating your own forward and backwards buttons
You can create buttons that make use of the internal system actions that control the forward and backward behaviour.
var strForwardButton = CRM.Button("Forward","forward.gif",CRM.URL(522));
var strBackButton = CRM.Button("Back","back.gif",CRM.URL(521));
myBlock.AddButton(strForwardButton);
myBlock.AddButton(strBackButton);
Hiding ASP Pages from the Forward and Back buttons
In ASP pages we can edit the include file so that the page is not stored in Sage CRM's history.

1) Make a copy of the include file (accpaccrmnolang.js or eware.js)
2) Change the nohistory parameter in the CRM.Init() method
change

eMsg = CRM.Init(
Request.Querystring,
Request.Form,
Request.ServerVariables("HTTPS"),
Request.ServerVariables("SERVER_NAME"),
false,
Request.ServerVariables("HTTP_USER_AGENT"),
Accept);

to
eMsg = CRM.Init(
Request.Querystring,
Request.Form,
Request.ServerVariables("HTTPS"),
Request.ServerVariables("SERVER_NAME"),
true,
Request.ServerVariables("HTTP_USER_AGENT"),
Accept);

3) Reference this new file in your ASP page

Note: This does not affect the recent list, only the back & forward navigation buttons.