Prior users rights

An interesting special set of circumstances governing patents apply in the case of so called prior users rights. These rights may arise in some countries to companies who can prove they were secretly operating a process or making a product, or had made effective and serious preparations to do so, prior to the patenting of that... 

One of the best tools for column inspection is a checklist. Table 10.1 illustrates the type of checklist preferred by the author for new internals. For each satisfactory item, a tick is entered, for each unsatisfactory item, a number is entered and a comment is spelled out on a separate sheet. Items not applicable are left blank. Design values and relevant tolerances are entered in the right-hand columns prior to inspection. Any alternative checklist can be satisfactory as long as it is sufficiently detailed and the user is comfortable with it. 

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