The ability to use embedded pattern-match modifiers, (?imsx), preceded the existence of the switches. It is, therefore, the switches that are the alternative. There is no switch for (?x), which allows white space and comments within an expression. You cannot use (?g) to replace the "g" switch.
Actually. the embedded modifiers and the switches are not alternatives, since they can produce different results. I only ever use the "g" switch.

To prefix an element replace [^] with [my prefix]. In a similar fashion use $ to suffix.

Thanks, that's great information! I've updated the page.

Can you give an example for the X-switch? With comments, do you mean something preceeded by # ? or how does that work?

Also, is there some kind of example on how the checkboxes and the embedded modifiers work differently?

[(?s)^.*?>(\d+)<.*?<b>([^<]+).*?>(\d{4})<.*] could become
[(?sx)^ .*? >(\d+)< .*?<b>([^<]+) (?#part 2 of date).*?>(\d{4})<.*]
The white space is ignored as well as the comment.
It's probably not all that helpful in the Pipes context.

To see some differences between the switches and the embedded modifiers use my copy of the gymnastics pipe. You can use the URL http://64.233.183.104/search?q=cache:WxZ... (possibly without the client parameter). At the time I tried the Google link the cache pointed to the old page. The images don't show up using the cached version. Anyway, just substitute all the (?s) modifiers for the "s" switch. The whole thing just goes to pot. I did try and work out how they were different but gave up.

Hi guys, great idea!

Im having some trouble with a little regex. Im filtering a url which has \ codes. as...
http:\/\/s3.amazonaws.com\/twitter_production\/profile_images\/75075164\/twitter_bird_profile_normal.png ... but cant seem to remove them.

Any help?

Thanks :)

Please supply a link to your pipe.