Charlie Hoffman has added an interesting post to his blog about using Magnify to verify the integrity of a financial report.

Our Magnify XBRL review tool comes built in with a range of generally applicable XBRL quality checks, as well as some jurisdiction-specific filing rules, such as the Edgar Filer Manual and HMRC’s Joint Filing Common Validation Critieria rules, but as Charlie demonstrates, the real power of Magnify comes from the ability to drop in custom rules.

Magnify’s checklist view allows users to build a custom, structured review based on checks that can be implemented in a range of technologies. The fastest way to build rules that operate on the XBRL semantics of a report is Sphinx. We do also support the XBRL International Formula standard, but as Charlie notes, “creating Sphinx rules is much, much easier”.

Charlie’s published the source to the rules that he’s using. Although readable, they look a little bland in this plain text format. Sphinx rules are most easily developed using SpiderMonkey which provides a rules development environment with syntax highlighting, concept drag-and-drop, and on-the-fly syntax validation.

There are a few neat features to note in the rulebase. The first one is these few lines:

transform
namespace "http://xbrl.us/us-gaap/2009-01-31"
       to "http://fasb.org/us-gaap/2011-01-31"

transform
namespace "http://xbrl.us/dei/2009-01-31"
       to "http://xbrl.sec.gov/dei/2011-01-31"

These two “transform” statements make all of the rules in the rulebase, which are written against the 2011 US GAAP taxonomy, also work with the 2009 US GAAP taxonomy. Once it’s published, two more lines will extended them to work with the 2012 taxonomy. Obviously this depends on the relevant concepts existing in both versions of the taxonomy, but where they don’t you can add some additional, more granular, transform statements to provide the necessary mappings. What’s more, if you happen to have an XBRL Versioning Report, you can easily generate the necessary transform statements.

Another thing to note about the rules is that they contain everything needed to generate the checklist that Charlie includes in the screenshot. Our validation platform is about more than just defining and executing validation rules. It’s about building a powerful and intuitive review environment:

Magnify screenshot