Binary package “qt4-doc” in ubuntu xenial

Qt 4 API documentation

 Qt is a cross-platform C++ application framework. Qt's primary feature
 is its rich set of widgets that provide standard GUI functionality.
 This package contains the complete Qt 4 API documentation (new help format).
 The documentation is provided in the new help format and manpage format;
 the new help format version can be viewed in conjunction with the Qt Assistant
 found in the qt4-dev-tools package.