DX Wombat, you say:
"No, it's 129.40 to clarify that you have not abbreviated 129.25, or 129.50 or 129.75 etc to a single figure."
That is not correct in the UK. In CAP 413 (the CAA Radiotelephony Manual), Edition 21, it is clearly stated in para 2.15:
"All six figures shall be used when identifying frequencies irrespective of whether they are 25 kHz or 8.33 kHz spaced. Exceptionally, when the final two digits of the frequency are both zero, only the first four digits need be given."
As a holder of a CAA R/T licence, you should know this, and not be posting incorrect phraseology online. There is enough of it being used as it is.
The way of ascertaining that a .250 or .750 frequency has not been incorrectly abbreviated is by using all six digits, and ensuring that any readback contains all six digits and ends in a zero, as shown in the final example of my previous post.
I am not certain about the rest of the world, but my reply was to a poster with a stated location of England, so I quoted the UK rules.