The phpwcms support forum will help to find answers to your questions. The small but strong community is here since more than 10 years.
http://www.markcarey.com/googleguy-says/Many people believe that you can use an underscore to separate_words_in_an_url, and that Google will recognize the words and count them for ranking purposes. I have read many debates about this: some people believe that Google indeed counts underscores as word separators, while other webmasters claim that you must use a hyphen or other character for Google to recognize the words as distinct. GoogleGuy has hinted in the past that hyphens are preferred. Recently, this debate reheated when Google made a change to it's "search word highlighting" feature in the search results: suddenly, keywords separated by underscores were being displayed in bold. The question then became whether the change was part of the ranking algorithm, or just the display mechanism.
Today, GoogleGuy finally confirmed this without any shadow of a doubt: "If you use an underscore '_' character, then Google will combine the two words on either side into one word. So bla.com/kw1_kw2.html wouldn't show up by itself for kw1 or kw2. You'd have to search for kw1_kw2 as a query term to bring up that page." I think we can put that debate to bed finally, at least for now.
es zählt das Ergebniss aus von Google.com und da sieht es seit kurzem (umstellung von Google) leider schlechter aus: 
, die den Stein der Weisen gefressen zu haben scheinen, aber gar nicht oder nur mit Blah Blah aus Ihrer Arbeit erzählen wollen. 
eben weil ich mit Link und Gegenlink arbeite und vielleicht auch ein glückliches Händchen hatte. Aber ich WILL WISSEN was an dieser Vorgehensweise besonders oder anders ist bzw. welche Erfahrungen andere dazu gemacht haben! 
