Availability::- use_module(library(uri)).(can be autoloaded) 
 [det]uri_encoded(+Component, 
+Value, -Encoded)
[det]uri_encoded(+Component, 
-Value, +Encoded)Encoded is the URI encoding for Value. When 
encoding (Value
[det]uri_encoded(+Component, 
+Value, -Encoded)
[det]uri_encoded(+Component, 
-Value, +Encoded)Encoded is the URI encoding for Value. When 
encoding (Value->Encoded), Component 
specifies the URI component where the value is used. It is one of query_value, fragment 
or
path. Besides alphanumerical characters, the following 
characters are passed verbatim (the set is split in logical groups 
according to RFC3986).
- query_value, fragment
- "-._~"|"!$'()*,;"|":@"|"/?"
- path
- "-._~"|"!$&'()*,;="|":@"|"/"