Business rights, trademarks, copyrights, patents and other franchises are assets only if they are acquired by purchase.
Such intangible assets as referred to in the preceding paragraph shall be valued at cost less the amount amortized for each period.
The cost of intangible assets shall be amortized in equal annual installments in accordance with the following prescribed number of years of amortization; provided that Where an intangible asset after acquisition cannot be amortized according to the prescribed number of years of amortization on account of specific reasons, an application stating the reasons therefore may be submitted to the collection authority-in-charge for permission to amortize in a different manner:
1. Amortization of business rights shall be based on a period of ten years;
2. Amortization of copyrights shall be based on a period of fifteen years;
3. Amortization of trademarks, patents and all other franchises may be based on the number of years of enjoyment of such rights after acquisition.