The Revised edition is based on the author's paper "Characterising Locally Finite Groups Satisfying the Strong Sylow Theorem for the Prime p" which has been published on pp. 13-39 of Volume 13 of the very fine open access mathematical journal Advances in Group Theory and Applications (AGTA) (see https://www.advgrouptheory.com/journal/#read). For that paper the author has transferred the copyright to AGTA. The Revised edition introduces quite a number of corrections and embellishments, highlighted in light green, which could not have been considered by AGTA, and especially a much more beautiful line and page formatting. For these enhancements the author has kept the copyright. The Revised edition adds Pages i to vi, Pages 26a to 26f and Pages xiii to xviii to the AGTA paper which either are required for a book - the front matter (die "Titelei") - or describe related aspects and background which cannot be published in a mathematical journal. The Revised edition incorporates major revisions by the author and by editors as well as some supplementary material designed to bring the research paper up to date.