• Multiple encoding of the same characters, most often seen with quotes and apostrophes.
• Mismatched input and output encoding of certain extended characters, most often seen with curly quotes, long dashes (em-dash), ellipses, etc.

Often you will see these appear when you are combining feeds from multiple sources through an external aggregater or external filter such as Yahoo pipes. Misconfigured web sites as well as some WordPress themes and plugins can also cause this. You might also see these characters appear with certain character sets shown on certain browser versions.

Character encoding problems are very common and are often seen in feed aggregators such as Google Reader.

The Problem

The characters appear because the current character set encoding incorrectly displays a character value. There are a number of different character sets used in data processing and each character set has unique availability and numbering of localized and international characters. ASCII, ISO 8859-2, Windows-1250, and UTF-8 are all common character sets, each with their own encoding schemes.

Because each character encoding is different a value encoded with one character set will display incorrectly with another character set. Since many character sets are extensions of ASCII, most of the basic Latin characters will show up correctly but will not correctly convert special characters such as curly quotes or long dashes. So while a long dash might appear correctly with one character set, in another character set it might be an upside down exclamation point, an accented letter, or not even exist at all.

Here is an example of incorrect character set conversion:

Blog » Blog Archive » Example Post

The more common problem is when a character is encoded or escaped for processing but never converted back. Because certain characters have special meaning with programming languages, SQL statements, scripting languages, and browsers, most often you will see text escaped or encoded before processing. When escaped or encoded text is escaped or encoded again, the result is an incorrect character when decoded.

Here is an example of double encoding or escaping:

‘This Title€™ Isn’t Displaying Correctly

Here are a few things you can try that might help:

• First, make sure the problem occurs on actual posts. Sometimes these characters show up when you preview the feed processing, but not on the blog itself.
• Try a different WordPress theme.
• Check your feeds at feedvalidator.org and also make sure the charset is correct.
• Check and/or fix your character set configuration

There are several Twitter RSS feeds available, depending on what you want to show. These feeds are as follows:

Public Timeline

Description: Returns the 20 most recent status updates from non-protected users who have set a custom user icon.

http://­twitter.com/statuses/public_timeline.rss

Friends Timeline

Description: Returns the 20 most recent status updates posted by yourself and that your friends. Note that this feed requires authentication by replacing <username> and <password> with your own username and password in the URLs below.

http://<username>:<password>@twitter.com/statuses/friends_timeline.rss

Optional Parameters:

• since.  Optional.  Narrows the returned results to just those status updates created after the specified HTTP-formatted date, up to 24 hours old.  The same behavior is available by setting an If-Modified-Since header in your HTTP request.  Example: http://<username>:<password>twitter.com/statuses/friends_timeline.rss?since=Tue%2C+27+Mar+2007+22%3A55%3A48+GMT
• since_id.  Optional.  Returns only statuses with an ID greater than (that is, more recent than) the specified ID.  Example: http://<username>:<password>twitter.com/statuses/friends_timeline.rss?since_id=12345
• count.  Optional.  Specifies the number of statuses to retrieve. May not be greater than 200.  Example: http://<username>:<password>twitter.com/statuses/friends_timeline.rss?count=5
• page. Optional. Example: http://<username>:<password>twitter.com/statuses/friends_timeline.rss?page=3

User Timeline

Description:  Returns your 20 most recent status updates or the updates from the user specified by the ID. Note that this feed requires authentication by replacing <username> and <password> with your own username and password in the URL below.

The RSS feed for your own posts is as follows:

http://<username>:<password>@twitter.com/statuses/user_timeline.rss

To get the feed for another users’ post, use either their user number or user name like this:

http://<username>:<password>twitter.com/statuses/user_timeline/21336467.rss or http://twitter.com/statuses/user_timeline/autoblogged.rss

Note that the username and password are not required if you are pulling the timeline of another user that is not configured as protected.

Optional Parameters:

• count.  Optional.  Specifies the number of statuses to retrieve. May not be greater than 200.  Example: http://<username>:<password>twitter.com/statuses/user_timeline.rss?count=5
• since.  Optional.  Narrows the returned results to just those statuses created after the specified HTTP-formatted date, up to 24 hours old.  The same behavior is available by setting an If-Modified-Since header in your HTTP request.  Example: http://<username>:<password>twitter.com/statuses/user_timeline.rss?since=Tue%2C+27+Mar+2007+22%3A55%3A48+GMT
• since_id.  Optional.  Returns only statuses with an ID greater than (that is, more recent than) the specified ID.  Example: http://<username>:<password>twitter.com/statuses/user_timeline.rss?since_id=12345
• page. Optional. Example: http://<username>:<password>twitter.com/statuses/user_timeline.rss?page=3

Note that you can view the full Twitter API documentation here: http://apiwiki.twitter.com/REST-API-Documentation

Post Templates

Since a Twitter update is just a single line of text, the content in the feed is the same as the title. For that reason, you might want to leave the post template empty for Twitter feeds. However, if you do want to use a post template, here are some variables that might be useful:

%link% – This is the URL that points to the individual tweet on the web.

%source_url% – This is the URL that points to the archive you are pulling from.

%icon% – The twitter icon.

Here is an example post template that might work well for Twitter:

<p><img src=”%icon%” alt=”Twitter” /><a href=”%link%”>Twitter update</a>:  %description%</p>
<p>More here: <a href=”%source_url%”>%source_url%</a></p>

Note that beginning with AutoBlogged v2.4.23, you will be able to change the title of a post by using the Custom Fields feature. To do this, edit the feed, scroll down to the Custom Fields setting, and enter title in the Custom Field box then something like “Twitter Update” in the Custom Field Value box.