Font Sizes: Only integers? Except MS Office

I've known this for awhile now, but in MS Word at least, and probably MS Excel as well, I can make my font sizes like 11.5, or something like that, and it'll take it just fine.

Recently, I started customizing an app called Foobar2000, which if you don't know, is basically a music player for PC for your audio library. When attempting to change the font size to something that wasn't an integer (for instance, 11.5, again), I would get this error message:

Font
Size must be a number.

I would Google this, assuming it was Foobar2000 specific and find no answer. My curiosity got to me, so I went ahead and tried it in Notepad, where I got the exact same error message. So, this leads me to believe that for whatever reason, using decimals in font sizes seems to only work with MS Office, and therefore the error message received was not Foobar2000-specific. I'd like to know why that is and if there is a way around it, as I'm very interested in taking advantage of non-integer font sizes.

Is there a way around this?

The standard font selection dialog used by most applications accepts only integer font sizes. The error message you are seeing comes from the dialog. Some more advanced applications, such as MS Word use their own dialog with more capabilities. Some applications allow entry of non integer sizes but round to the nearest integer. When using software you did not create you must accept the decisions made by the developer. They must make many decisions and it is impossible to please everybody.