Do take a good look at the link I posted above, it will show you a good clear example of a Tughra. Are there any other marks on the bottom or in the design of the cup?
Let me give this a little context. It became standard practice in the Ottoman Empire to use different languages and calenders to administer this huge geographic land mass. This practice on some level carried on into the Republic as you see in the bottom of the cup; Ottoman, Armenian, and Roman characters. What the cup appears to lack if it was created in the time of the empire is a pressed Tughra mark, the 800/900 mark, and/or the zigzag scratch mark also commonly seen.
The Holy Qur'an was written in Arabic of the particular tribe, the Quraysh, of which the Prophet (SAW) belonged. For the 1.7 billion Muslims living in the world today Arabic is not our primary language, as it was for the Ottomans. Turkic languages are in themselves vast, many forms. One method was to use Arabic characters to write the most common form used by the Ottoman elite.
Arabs or other Muslims who are Arabic literate or more precisely fluent in Qur'anic Arabic can not read it. The numerous accent marks contained in Qur'anic Arabic enable all Arabic speakers whether you live in Saudi Arabia, the Gulf States, Syria, Egypt, Morocco, etc to be able to read and understand it clearly. Arabic like Hebrew is a very flexible language open to interpretation. That's a whole different issue.
Part of the reason I was asking Damon if he was Turkish was many Turks today have not been taught Ottoman Turkish, it is not used to the best of my knowledge unless your a scholar or calligrapher. The passages on the outside of the bowl may be Ottoman, at the time they were inscribed the language may have still be in use.
I pray you found this useful.