As Sam Ruby has pointed out, Loïc Le Meur's name is a good test of a simple encoding issue faced by RSS publishers: When a word contains a character with a diaresis or similar mark, how do you properly format the word so that the character is presented correctly by aggregators?

I tested this with single escaping ("Loïc Le Meur") and double escaping ("Loïc Le Meur") in Internet Explorer, Firefox, Bloglines, My Yahoo and NewsGator online.

Test files

http://www.rssboard.org/files/test-single-escaped.xml http://www.rssboard.org/files/test-double-escaped.xml

The Feed Validator reports both files as valid RSS, but the double-escaped version has two warnings that channel title and item title should not contain HTML.

I'm going to do more tests on other aggregators, and if anyone else would like to do the same, that would be helpful. I'll invite some aggregator developers to look this over as well.

Aggregator tests

1. Bloglines

INPUT: Loïc Le Meur (single escaped)

PRESENTATION:

Channel Title: Loïc Le Meur
Channel Description: A weblog about Loïc Le Meur
Item Title: Loïc Le Meur Joins RSS Board
Item Author: By loic@example.com (Lo[bad character]c Le Meur)
Item Description: Loïc Le Meur has joined the RSS Board
Item Category: on Loïc Le Meur

INPUT: Loïc Le Meur (double escaped)

PRESENTATION:

Channel Title: Loïc Le Meur
Channel Description: A weblog about Loïc Le Meur
Item Title: Loïc Le Meur Joins RSS Board
Item Author: By loic@example.com (Lo[bad character]c Le Meur)
Item Description: Loïc Le Meur has joined the RSS Board
Item Category: on Loïc Le Meur

CONCLUSION: Single- and double-escaping produce the same result. All elements present his name correctly except for item author, which contains a bad character under either escaping.

2. Internet Explorer

INPUT: Loïc Le Meur (single escaped)

OUTPUT:

Channel Title: Loïc Le Meur
Channel Description: A weblog about Loïc Le Meur
Item Title: Loïc Le Meur Joins RSS Board
Item Author: - loic@example.com (Loïc Le Meur)
Item Description: Loïc Le Meur has joined the RSS Board
Item Category: Loïc Le Meur

INPUT: Loïc Le Meur (double escaped)

OUTPUT:

Channel Title: Loïc Le Meur
Channel Description: A weblog about Loïc Le Meur
Item Title: Loïc Le Meur Joins RSS Board
Item Author: - loic@example.com (Loïc Le Meur)
Item Description: Loïc Le Meur has joined the RSS Board
Item Category: Loïc Le Meur

CONCLUSION: Single-escaping presents his name correctly on all elements. Double-escaping doesn't, except for item description.

3. Firefox 1.0.5.1

INPUT: Loïc Le Meur (single escaped)

Channel Title: unsupported
Channel Description: unsupported
Item Title: Loïc Le Meur Joins RSS Board
Item Author: unsupported
Item Description: unsupported
Item Category: unsupported

INPUT: Loïc Le Meur (double escaped)

OUTPUT:

Channel Title: unsupported
Channel Description: unsupported
Item Title: Loïc Le Meur Joins RSS Board
Item Author: unsupported
Item Description: unsupported
Item Category: unsupported

CONCLUSION: Firefox only supports item titles. Single-escaping presents his name correctly, double-escaping doesn't.

4. My Yahoo

INPUT: Loïc Le Meur (single escaped)

OUTPUT:

Channel Title: Lo[bad character]c Le Meur (on Add Content form), no title at all (on My Yahoo home page after adding content)
Channel Description: unsupported
Item Title: Loïc Le Meur Joins RSS Board
Item Author: Unsupported
Item Description: Unsupported
Item Category: Unsupported

INPUT: Loïc Le Meur (double escaped)

OUTPUT:

Channel Title: Loïc Le Meur (on Add Content form), no title at all (on My Yahoo home page after adding content)
Channel Description: unsupported
Item Title: Loïc Le Meur Joins RSS Board
Item Author: Unsupported
Item Description: Unsupported
Item Category: Unsupported

CONCLUSION: Single- and double-escaping works for item titles and doesn't work for channel titles.

5. NewsGator Online

INPUT: Loïc Le Meur (single escaped)

OUTPUT:

Channel Title: Loïc Le Meur
Channel Description: unsupported
Item Title: Loïc Le Meur Joins RSS Board
Item Author: [loic@example.com (Loïc Le Meur)]
Item Description: Loïc Le Meur has joined the RSS Board
Item Category: Unsupported

INPUT: Loïc Le Meur (double escaped)

OUTPUT:

Channel Title: Loïc Le Meur (on My Feeds page), Loïc Le Meur (on My Feeds sidebar), Loïc Le Meur (on feed display page)
Channel Description: unsupported
Item Title: Loïc Le Meur Joins RSS Board
Item Author: [loic@example.com (Loïc Le Meur)]
Item Description: Loïc Le Meur has joined the RSS Board
Item Category: Unsupported

CONCLUSION: Single- and double-escaping produce the same result. All elements present his name correctly except for one page channel title appears in double-escaping.