Re-denting (RD) is comparable to re-tweeting (RT) in Twitter (and see minor note about Twitter repeat nicety below).
In the web and many other interfaces (e.g., Android client), identi.ca and other StatusNet instances feature a Repeat button with each notice (alongside Fave and Reply buttons). The Repeat button looks like a recycle symbol.
If your interface features the Repeat button, just click Repeat! No need to read the manual repeating instructions below.
Avoid duplicates to groups. If the notice includes a group name, prefixed with an exclamation mark:
- remove that exclamation mark before re-sending
- optional: replace ! with # to leave a hash tag in place of the group link (example). Some client software has settings to do this for automatically.
(Please note that if you use the statuses/retweet API method, repeated notices which include a group name won't be duplicated in groups timeline.)
Symbols such as ♺ are unrecognizable to some clients. If in doubt use the RD prefix
Composing a notice with re-dents in mind
If you expect your notice to be repeated by others, don't let the character countdown drop too low. Consider that the person repeating will typically begin it with RD @ .
- if your username is seven characters long, aim to not drop below 12 in the countdown
- RD @johndoe the quick brown fox jumped over the #lazy #dog — that's twelve characters before the word the.
Hint: put the most disposable part of your notice, maybe the hash tags, at its tail.
Propagating repeats to Twitter
If you have Identi.ca or another StatusNet instance copy your dents to Twitter, you'll want to "connect" your accounts (click "Connect" at the top of identi.ca and most StatusNet themes). This way repeats show up "natively" in Twitter when possible (when the person you're redenting has also linked their identi.ca/statusnet and twitter accounts) even if identi.ca/statusnet and twitter account names are different.
If you automatically send notices from Identi.ca to Twitter but prefer to not Send local "@" replies to Twitter:
- keep the @ symbol at the beginning of the reply.
The bigger the group, the more it is important to think about what you post.
- Before posting always think about how many people you are going to reach and how many people may be interested in you particular dent.
- Example of a "good" dent: Since this morning !linux is the most used operating system in the world: www.example.com/linux-article
- Example of a "bad" dent: Just re-installed !linux on my laptop
- Think carefully before redenting to a group. It's usually a bad idea. Since the dent came from the group, you'll be resending it to all the same people who just got it. It creates wasted traffic to send the same notice again and again to the same people.
- If you post in non-English, think about how many people understand your post and how many won't (obviously this does not concern local groups).
When to use a group tag or a hashtag
As noted above you should consider how many in the group will be interested in your dent before using a group tag. In some situations a hashtag may be more appropriate.
- Hashtags can be used to search for dents on a particular topic. If your dent is just saying "this is about x" then a hashtag may be best
- Group tags are used to send a dent to all group members. If your dent is saying "This information may be useful to the group" then use a group tag.
If denting this: Downloading latest version of !Ubuntu !Linux it would probably be more appropriate to use hashtags instead: Downloading latest version of #Ubuntu #Linux.
If denting this: Any suggestions for good vector gfx programs for #Linux?, it might be better to use a group tag: Any suggestion for good vector gfx programs for !Linux?
Naming and purpose
Avoid names that are contentious.
If the name (or purpose) that you have in mind overlaps with an existing group, contact an administrator of that group before proceeding.
Administering a group
Never forget: With great power comes great responsibility 
- Upload a group logo.
- Write a good description:
- Try to avoid the word group in the group description. It's redundant.
- If appropriate, make use of the alias feature.
- Don't be the only admin. You can't be online all the time.
- Try to get admins from other timezones.
Avoid posting links without an adequate description of what the link is. This particularly applies if you are using a URL shortener.
- If you don't need to use these, resist. Most readers will prefer a transparent URL.
Avoid multiple steps. If a short URL leads to something other than an original (examples: http://digg.com/u3GXXf http://www.diigo.com/0852b) consider that readers may prefer a single step to the original.