We've found glitches somewhere in Scratch, right?
The point is, you should have. Before reporting a bug, clear your cache to see if your issue is a caching issue. If it's fixed, stop here. Your bug was down to your cache. The first thing you want to do is make a new topic. Alternatively, you can hit the blue button in the corner of the Bugs and Glitches (BaG) forum that says new topic.
For a subject, summarise your glitch in a few words. In my example, I'm going to use “Character limit stays red if limit hit after comment posted”. Yes it's jank. Yes it's being fixed, but hey. Why not?
In the main topic, you want to include the following things:
A bug description
When it started
Where it is
A link (if it's in a specific project, link to it)
Operating system, browser and Flash version (should be already there. if not, click the globe icon in the tools bar above the topic itself)
Screenshot (even better if you record a GIF. I recommend using ScreenToGif)
Trying to be as descriptive as possible will help a lot.
Animated tutorial (middle click to enlarge):
So what if there's a topic to reply to?
Glad you asked. Preferably, there are these codes you should follow. They're the way to reply to a bug.
NAB - Not a bug - Used if the topic is not on the topic of the forum or if the “bug” is intended.Please include as much information as possible. The more information you provide, the more helpful it is to everyone.
Dupe - Duplicate - There's another topic. Preferably link to it.
Known - Does what it says on the tin - This is different to Dupe. This means the Scratch team knows (with reference) about the bug.
CNR - Cannot reproduce - Include your system specifications.
CR - Can reproduce - Include your system specifications.
LOI - Lack of information - Asks the person to provide more information about the bug. Tell them what is missing and to include it.
Since this topic is far from perfect, reply to this if you have a suggestion, need help or have a question.