#CNostr can't load some images because the wall，if give two or more urls will same picture show many times and waste data traffic .

So can we #Nostr like HTML img tag onerror：

```

onerror="javascript:onerror = null; this.src='URLpic2.gif';"

alt="pic" />

```

#Markdown can add alt tag but rarely use，so we can use `` add a Two-Urls-Pic，Only load pic1 if pic1 can load， if fail load pic1，load pic2 at the same place.