Reploids being what they are -- essentially people in metal skins -- they have developed their own little unique idioms and cultural ideas over the last few decades. These notes are here to help those of you RPing as robots get an idea of some of the concepts and taboos of reploid society. (It should be noted for sake of reference that Robot Masters and Androids are considered 'reploids' in standard vernacular.)
This is extremely important to a reploid; every robot is created because there's a specific task they were needed to accomplish. Whether it's saving the world or sweeping up the castle, the reploid's very mind and concept of self is molded around that specific function; it is the window through which their perception of life and their patterns of thought are shaped. This is the fundamental difference between humans and reploids; humans are born searching for a purpose, while reploids are only born to fill one.
Reploids that are created for no purpose or do not know their purpose (a rare instance indeed caused by misfortune, accident or cruelty) are often distressed and full of self-loathing, doubt and shame, and struggle to find a purpose for themselves. To insinuate or outright state that a reploid was created without a purpose is to call them the equivalent of a bastard -- an illegitimate birth that is a great source of shame and dishonor. Reploids that change their purpose or refuse to accept it (outside of upgrade, survival circumstances or reconditioning) are looked upon as deviants, subjects of curiosity or suspicion. Reploids are born to fulfill a task, and those that refuse to do so of their own will are thought to have mental irregularities. Reploids that change their purpose for personal reasons often try to hide what their original purpose was.
This is an extremely insulting term to use against a reploid, insinuating that they are malfunctioning, never worked correctly, were created poorly, and that no one cares enough to repair them. "Defective" is considered similar to a profoundly insulting racial slur.
Unless used to talk about the actual drone robots, calling a reploid a mechaniloid or automaton is telling them they're stupid, brute animals. Equivalent of 'stupid' or 'retarded' or other intelligence-based slurs. Particularly insulting if used by a human.
As reploids don't procreate in the standard biological fashion, a reploid's sense of relations and family are different than human generations and relations. Concepts such as mother, father and siblings become matters of choice and acceptance between reploids, rather than roles that the accident of birth has assigned them. Reploids can have multiple parents or none at all; they can choose to call another reploid sister or brother or reject sibling-hood even among groups created by the same human or organization.
Reploids still have a human desire for family and social interaction; imitating their human creators and forebears, most reploids consider themselves related to another if they share the same creator, the same model type, or are created from the same DNA soul. Humans, seeing reploids as being "human enough" through their human-like behavior and mental capacity, also tend to mold reploid groupings into families and impress these social boundaries upon reploids almost subconsciously, attempting to match reploids to understood human paradigms. This can sometimes be unfair to reploids who are accused of "incest" or other human sexual perversions when they find themselves pair-bonding with another reploid humans have dubbed a "sibling" or "parent".
Among reploids, the following "family" statuses are usually assumed:
If a reploid is created using the DNA of another robot as a base, they tend to look upon that robot as a parent. If a group of reploids are created from the DNA of another, this group tends to regard themselves as siblings (Example: The four MMZ Guardians). Reploids created by splitting a DNA soul (a very, very rare occurrence that requires enormous technological skill to pull off) consider themselves twins (or other multiples). Examples of this would be Midi and Techno, or Colonel and Iris.
Reploids created by the same individual look to that individual as a parent, and consider themselves siblings. In the cases of reploids created by a corporation or mass produced at a particular factory, they may tend to observe clan, tribal or even racial identity (Example: Pantheon Robotics reploids tend to feel themselves as being a superior "race" among reploids in general, and are more likely to work with one another than other reploids). The Eldest or strongest of these groups tend to assume a 'clan leader' or 'firstborn' status, regardless of whether or not there is a 'parent' among them.
Reploid models are not intrinsically unique; many time a successful design is replicated several dozen, hundred, or even thousand times, resulting in groups of individual reploids who share the same appearance and function, but different names or serials. Reploids of the same model or same production batch tend to feel a shared identity and closeness that ranges from sibling-hood to classmates.
Due to the fluidity of reploid "family" structures, there are often further permutations and strange groupings made simply by the choice of the reploids involved. And as always, there are some reploids who find that "family" is a needless human trapping, rejecting the notions altogether.