Final answer:
The RDF term used as an argument for URI() and IRI() must be a string that conforms to the URI or IRI specification, which includes characters that form a valid identifier for a resource.
Step-by-step explanation:
To answer your question, when using RDF (Resource Description Framework), the term that you use as an argument of URI() (Uniform Resource Identifier) and IRI() (Internationalized Resource Identifier) functions must be a string that conforms to the respective URI or IRI specification. This means that it should be a sequence of characters that forms a valid identifier for a resource. For URIs, this typically adheres to a scheme such as http, https, or ftp, followed by a colon and then a string that identifies the resource within the context of that scheme. For IRIs, which are a superset of URIs, the sequence of characters can also include characters from the Universal Character Set (Unicode/ISO 10646), which allows for a wider range of symbols and language-specific characters.