<P> Informed Consent Form Templates can be found on the World Health Organization Website for practical use . </P> <P> Informed consent can be complex to evaluate, because neither expressions of consent, nor expressions of understanding of implications, necessarily mean that full adult consent was in fact given, nor that full comprehension of relevant issues is internally digested . Consent may be implied within the usual subtleties of human communication, rather than explicitly negotiated verbally or in writing . In some cases consent cannot legally be possible, even if the person protests he does indeed understand and wish . There are also structured instruments for evaluating capacity to give informed consent, although no ideal instrument presently exists . </P> <P> Thus, there is always a degree to which informed consent must be assumed or inferred based upon observation, or knowledge, or legal reliance . This especially is the case in sexual or relational issues . In medical or formal circumstances, explicit agreement by means of signature--normally relied on legally--regardless of actual consent, is the norm . This is the case with certain procedures, such as a "do not resuscitate" directive that a patient signed prior to their illness . </P> <P> Brief examples of each of the above: </P>

History of informed consent in the united states