A recent interesting Federal Court decision in favour of Mantra, that decides that the onsite manager can own a trademark for its letting business, even if the trademark is similar to the building name.
Mantra IP Pty Ltd v Spagnuolo  FCA 769 (19 July 2012):
"Like the Chifley Tower, “Q1” was a sign devised by Sunland, a private entity, to, among other things, signify or name its private building development. When it chose the sign “Q1”, it did not adopt or incorporate a geographical name such as that of an established town, suburb or district, like Surfers Paradise, or the Gold Coast. ... From this history, I do not consider there is any basis upon which any trader could claim to have any “common right of the public” to make honest use of the sign “Q1” as a trade mark. Put differently, there is nothing about the sign “Q1” that could be said to bring it within the “common heritage”..."