Ann: Shareholder Letter - What Reagent Suite Does LIT Use, page-50

You can accrue almost all of your development costs an intangible asset - work in progress, and don't have to worry about the amortisation until you actually start using the 'asset' as long as it passes impatent testing. It would be interesting to see if SiLeach actually passes an impairment test, the intangible asset you are working on would need to be able to generate some form of income when it's complete. Not sure if SiLeach will ever do that..

The cost of the patent however could be recorded as a capitalised expense and amortised over a defined period. Again it has to actually succeed in gaining a patent for this to be capitalised.