For imaging of a structure, the structure is marked with a substance which can be converted by a switching signal from a first into a second state, and which provides an optical measurement signal in one of its states, only. A program is compiled using two compilers to generate first and second sets of object code. The comment relates to a particular portion of the video content. A method of making a dissolvable compressed tobacco product is also provided. In some cases, the building controller unit may include a license server for granting andor denying software access requests from one or more software applications running external to the building controller unit based on the software license information stored in the building controller unit. A picture pouch is used to protect the item in the scented picture frame from absorbing an aroma of the scent board.