If you want to remove the browser's Back button functionality in Sugarcane, to prevent the player from rewinding or undoing moves, here is some script code that can do that:

History.prototype.save=function(c){var a="";for(var b=this.history.length-1;b>=0;
b--){if((this.history[b].passage)&&(this.history[b].passage.id)){a+=this.history[b].passage.id.toString(36)+".";
}}this.history[0].hash="#"+a.substr(0,a.length-1);if(this.hash){return"";}this.hash=this.history[0].hash;
return this.hash;};History.prototype.restart=function(){window.location.reload();
};macros["return"]=macros.back={handler:function(a,b,e){var f=RegExp(String.fromCharCode(92)+".","g");
var c="";var d="";var f="";if(e[0]){if(e[1]=="steps"){if(isNaN(e[0])){throwError(a,"parameter before 'steps' must be a number.");
return;}else{if(e[0]<state.history[0].hash.match(f).length){d=state.history[e[0]].passage.title;
}}}else{if(tale.get(e[0]).id==undefined){throwError(a,"The "+e[0]+" passage does not exist");
return;}h=tale.get(e[0]);h=new RegExp("("+f.toString()+"|#)"+h.id.toString(36));if(h.test(state.history[1].hash)){d=e[0];
}}}else{d=state.history[1].passage.title;}if(!d){return;}else{el=document.createElement("a");
el.className="return";el.onclick=function(){state.display(d,el);};
el.href="javascript:void(0)";el.innerHTML="<b>«</b> "+b[0].toUpperCase()+b.slice(1);
a.appendChild(el);}}};

This will prevent previously visited passages from appearing in the player's browser history, except for the Start passage (since it's loaded before custom scripts are), and any passages revisited using the Rewind menu. (With this code, that seemingly vestigial menu could be made more important.)