familiar and unfamiliar people in both forms of the disorder. Such discrimination does exist as a feature of the social behavior of children with atypical attachment styles. Both DSM-IV and ICD-10 depict the disorder in terms of socially aberrant behavior in general rather than focusing more specifically on attachment behaviors as such. DSM-IV emphasizes a failure to initiate or respond to social interactions across a range of relationships and ICD-10 similarly focuses on contradictory or ambivalent social responses that extend across social situations. The relationship between patterns of attachment in the Strange Situation and RAD is not yet clear. There is a lack of consensus about the precise meaning of the term "attachment disorder". The term is frequently used both as an alternative to reactive attachment disorder and in discussions about different proposed classifications for disorders of attachment beyond the limitations of the ICD and DSM classifications. It is also used within the field of attachment therapy, as is the term reactive attachment disorder, to describe a range of problematic behaviors not within the ICD or DSM criteria or not related directly to attachment styles or difficulties at all. Research Research from the late 1990s indicated there were disorders of attachment not captured by DSM or ICD and showed that RAD could be diagnosed reliably without evidence of pathogenic care, thus illustrating some of the conceptual difficulties with the rigid structure of the current definition of RAD. Research published in 2004 showed that the disinhibited form can endure alongside structured attachment behavior (of any style) towards the child's permanent caregivers. Some authors have proposed a broader continuum of definitions of attachment disorders ranging from RAD through various attachment difficulties to the more problematic attachment styles. There is as yet no consensus, on this issue but a new set of practice parameters containing three categories of attachment disorder has been proposed by C.H. Zeanah and N. Boris. The first of these is disorder of attachment, in which a young child has no preferred adult caregiver. The proposed category of disordered attachment is parallel to RAD in its inhibited and disinhibited forms, as defined in DSM and ICD. The second category is secure base distortion, where the child has a preferred familiar caregiver, but the relationship is such that the child cannot use the adult for safety while gradually exploring the environment. Such children may endanger themselves, cling to the adult, be