As part of the requirement to limit patent applications to a single invention, the US Patent and Trademark Office sometimes issues restriction requirements citing differences among figures in an application.  A typical example is provided below, where the Office asserts that six different species are shown among various different figures.

However, there is an argument that such actions are not appropriate in the first place, since a restriction requirement must be made on the basis of claims in the application, rather than figures. 35 U.S.C. § 121 explicitly states that “[i]f two or more independent and distinct inventions are claimed in one application, the Director may require the application to be restricted to one of the inventions.”  It is noted that this statue specifies that restriction is made between inventions, which are defined in the same statue as that which is being claimed.  This point is highlighted in MPEP §806.01, which states “[i]n passing upon questions of double patenting and restriction, it is the claimed subject matter that is considered and such claimed subject matter must be compared in order to determine the question of distinctness or independence." Additionally, the MPEP also states that the particular reasons for the independence and distinctness should be given for each claim.  This is summarized in the MPEP at § 808.01, which states “[t]he particular reasons relied on by the examiner for holding that the inventions as claimed are either independent or distinct should be concisely stated” (emphasis added).   

Nevertheless, as a general rule the Office continues to maintain that figure-based restrictions are proper.  Of course, there are still further obvious problems with the above example, but those issues go beyond this post. 

One drafting tactic to minimize the ability for an Examiner to maintain figure-based restrictions with regards to different aspects of a claimed method is to utilize a linking flowchart, as well as nesting flowcharts (like sub-routines when coding).  Often the reasoning provided by the Office will not have considered that the flowcharts are actually linked together, and thus the Applicant can often make strong arguments as to how the different figures do not satisfy the requirement of patently distinct species.