nly represents a subject to be
divided but also a subclass including all other species not falling
within the indented titles. Indention does not indicate superiority or
inferiority, but merely that the title and the definition of the
indented subclass must be read with the title and definition of the
subclass under which it is indented. A title selected in a scheme of
subdivision to be of first importance and placed, therefore, in advance,
should not thereafter be indented under a title selected to be of
secondary importance and, therefore, having a lower position. (See Rule
8.)

(11) A group of material may be divided on several different bases.
"Use" or "purpose" or "object treated" may be adopted only when the
"use" or "purpose" or "object treated" stamps upon the invention such
peculiarities of operation or construction as to limit the applicability
of the invention to the use or purpose named. (See Basis of
Classification, Rule 1.) A group based upon mode of operation also may
be divided into subclasses (1) with a "functional" title, usually
participial in form, and adapted therefore to receive machines,
processes, and tools; (2) with special use, purpose, or object-treated
title containing the name of the use, purpose, or object; (3) with
"type" title, usually a name or a name with a qualifying adjective; (4)
with a title of a part or subcombination, also a name.

Example: In Class 90, Gear-Cutting, Milling, and Planing,
are to be found subclasses entitled "Gear-cutting," certain
machines being peculiar to that use; also other subclasses
with the general functional title "Planing," subordinate to
which are the special use subclass "Planing, Soft metal,"
and the type subclass "Planers" divided into two coordinate
subclasses, "Reciprocating bed" and "Reciprocating cutter,"
and several subordinate "part" subclasses, including
"Tool-feeds" and "Tool-heads." The adjective form of the
title "Planers, Reciprocating bed," indicates a type
subclass. If the title had been Planers, Reciprocating
beds, the indication would be that the subclass was a part
subclass to receive planer beds only. In the class referred
to for illustration, "Tool-feeds" and "Tool-heads" indicate
subclasses for parts and not for types of planers having
tool feeds.

(12) In arranging the divisions of a class, such arrangement should be
sought as will minimize the need of cross-references. Search fo