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In general, any Relevant Evidence is admissible. In criminal cases in particular, certain metas of evidence are inadmissible, except where there are exceptions in common law or statute. Each of these has its own entry in this glossary. The general exceptions include:

• 'hearsay', that is, a statement submitted at trial other than that given in oral proceedings which is submitted as being probative of the truth of its contents (e.g. Joe writing down or saying to someone "I saw a pig fly" being submitted as evidence of the truth that pigs fly as opposed to being evidence that Joe is mad) (see: Hearsay), ;
• 'opinion' (see: Opinion evidence), except where it is from a expert on matters that are expected to be outside the knowledge of the court;
• evidence that tends to show the bad character of the accused (see Evidence Of Bad Character), but is not related to the case in point (except certain items of 'Similar facts' evidence -- but be aware that this area of law is due for a radical shake-up in the CJA_2003);
• 'narrative' evidence, that is, evidence from prior statements made by a witness that would contradict his current position. Exceptions include Res Gestae utterances.

Certain items which were previously largely inadmissible in criminal cases are now usually admissible, owing to various statutory provisions:

• failures to answer questions which the accused might reasonably by expected to answer (see: Right to silence), as provided in the Criminal Justice And Public Order Act (1994);
• 'documentary hearsay' (see: Hearsay), particularly statements made to investigating officers and documents created in the course of business Criminal Justice Act (2003).

Even if the evidence is of a meta that is normally admissible, a court has the discretion under the Police and Criminal E v idence Act (1984) to exclude evidence in certain circumstances (see: Exclusion of evidence).