Cloud the bottom of the hierarchy. Clouds in the troposphere assume five physical forms based on structure and process of formation. These forms are commonly used for the purpose of satellite analysis. They are given below in approximate ascending order of instability or convective activity. "Non-convective" stratiform clouds appear in "stable" airmass conditions and, in general, have flat sheet-like structures that can form at any altitude in the troposphere. The stratiform group is divided by altitude range into the genera cirrostratus (high-level), altostratus (mid-level), stratus (low-level), and nimbostratus (multi-level). Fog is commonly considered a surface-based cloud layer. The fog may form
Machine-or-transformation test generally insufficient to make an otherwise ineligible method claim patent-eligible. The PTO Guidance Memo explains that "[t]his means the machine or transformation must impose meaningful limits on the method claim's scope [for it] to pass the test." What makes a limitation meaningful is unstated, but perhaps that concept can be defined in terms of whether the limitation places only an insubstantial limitation on claim scope or preemptiveness. The second corollary is that insignificant extra-solution activity will not transform a patent ineligible principle into a patentable process. The PTO Guidance Memo explains that "[t]his means reciting a specific machine or a