/usr/include/KDE/Syndication/ is in kdepimlibs5-dev 4:4.13.0-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KDE/Syndication/AbstractParser
/usr/include/KDE/Syndication/Category
/usr/include/KDE/Syndication/Constants
/usr/include/KDE/Syndication/DataRetriever
/usr/include/KDE/Syndication/DocumentSource
/usr/include/KDE/Syndication/DocumentVisitor
/usr/include/KDE/Syndication/ElementWrapper
/usr/include/KDE/Syndication/Enclosure
/usr/include/KDE/Syndication/Feed
/usr/include/KDE/Syndication/Global
/usr/include/KDE/Syndication/Image
/usr/include/KDE/Syndication/Item
/usr/include/KDE/Syndication/Loader
/usr/include/KDE/Syndication/Mapper
/usr/include/KDE/Syndication/ParserCollection
/usr/include/KDE/Syndication/Person
/usr/include/KDE/Syndication/SpecificDocument
/usr/include/KDE/Syndication/SpecificItem
/usr/include/KDE/Syndication/SpecificItemVisitor
/usr/include/KDE/Syndication/Syndication
/usr/include/KDE/Syndication/Tools