This is an announcement for the paper “Unconditionality of Periodic Orthonormal Spline Systems in $L^p$” by P.M. Berná<https://arxiv.org/find/math/1/au:+Berna_P/0/1/0/all/0/1>K. Keryan<https://arxiv.org/find/math/1/au:+Keryan_K/0/1/0/all/0/1>, M. Passenbrunner<https://arxiv.org/find/math/1/au:+Passenbrunner_M/0/1/0/all/0/1>. Abstract: Given any natural number $k$ and any dense point sequence $(t_n)$ on the torus $\mathbb{T}$, we prove that the corresponding periodic orthonormal spline system of order $k$ is an unconditional basis in $L^p$ for $1<p<\infty$. The paper may be downloaded from the archive by web browser from URL https://arxiv.org/abs/1708.09294