JSF 2.0 spec section 188.8.131.52 Resource Identifiers says this about libraryName :
"... The run-time must enforce the following rules to consider a <resourceIdentifier>s valid. A <resourceIdentifier> that does not follow these rules must not be considered valid and must be ignored silently.
- The set of characters that are valid for use in the localePrefix, libraryName, and resourceVersion segments of the resource identifier is specififed as XML NameChar excluding the path separator and ‘:’ characters. The specification for XML NameChar may be seen at http://www.w3.org/TR/REC-xml/#NT-NameChar."
- A further restriction applies to libraryName. A libraryName must not be an underscore separated sequence of non-negative integers or a locale string. More rigorously, a libraryName must not match either of the following regular expressions:
so any libraryName that contain slashes like in the example (components/mycomp) is considered invalid.