URL Rewriting to include arrays & SEO

I have rewritten a URL so it looks something like http://www.mywebsite.com/[COLOR=“#FF0000”]b:5,7,9,/c:5,7,9,/[/COLOR]

From an SEO standpoint, is the comma the best separator to use or is there a better character?

Thanks

Why would you want to pass arrays of data in your URL like that?

I have a dynamic page which updates via ajax based on user input. The output of products listed is based on user selection, a bit like a clothes website. I want the URL to be portable, so users and copy and paste it and get directly back to THAT page layout without having to make the selections over again etc.

I’m looking for the best blend between readability and SEO with probably more emphasis on the latter.

Thanks

Usually you’d pass the options via a query string, like this:
http://www.example.com/products?b=5,7,9&c=5,7,9

From an SEO standpoint, query strings represent options for changing how the data is displayed (eg. the order or number of items in a results list), where as in a URL like the example you gave, any change in the URL is considered a separate page (and should have different content). This: http://www.mywebsite.com/b:5,7,9,/c:5,7,9,/ would be considered a different page to this: http://www.mywebsite.com/b:5,7,9,/c:5,7,3,/

As for the readability, that could be improved by changing the name of your variables. Going back to the list results page example, you might have something like this:
www.example.com/products/shoes?size=9&sortby=price&sortorder=asc
here all the query string variables are logically named, and it’s easy to take a guess at what results the page is going to show me.

On the one hand that’s not necessarily a bad thing, afterall the pages will display different products / categories, but I have set a canonical link in the <head>… But that’s now got me thinking if the URL structure would cause me problems for the canonical… Google would see multiple pages with the same canonical? hmmm…

That being the case, then your urls should reflect that. The canonical link is only useful if you have a situation where you can access the same content via different URLs, and you want to prevent google from seeing it as duplicate content (which could adversely affect your rankings)

It’s difficult to give better advice without knowing more about your site and its structure, but you should always aim to make your URLs human-readable. URLs like http://www.mywebsite.com/b:5,7,9,/c:5,7,3,/ mean nothing to google, whereas URLs like www.mywebsite.com/products/productname and www.mywebsite.com/categoryname will help google index your site (as well as being better for your users).

Yeah, I appreciate that, it’s quite a complex structure making heavy use of ajax. I’ve got product categories, brands, prices, product type all updatable on the page without a refresh…

I think on reflection a better approach would be [FONT=courier new]http://www.mywebsite.com/products/brands:5,7,9&categories:5,7,3[/FONT] and have the canonical set to [FONT=courier new]http://www.mywebsite.com/products/[/FONT]