Traceability is defined as the possibility to correlate the various artefacts (from requirement to source code) generated when developing software. In the context of software product line development, the problem is made even harder due to some characteristics specific to this software development approach. In this paper we discuss these problems specific to traceability for software product line development. We propose a taxonomy of traceability links. We also present a model to manage traceability of design decisions in the presence of uncertainty.