Still struggling with Unicode

[Graham Samuel]

I know people are lining up for the conference (wish I was there!) so I am not sure who's listening, but here goes.

On advice from Fraser Gordon, I've been trying to use LC 7 to experiment with Unicode. I've had some tricky problems with the latest version in the LC 'downloads' catalogue (DP10), so I'm having to work somewhat in the abstract (I mean I can't get my actual app script to run, so I'm just using the Message Box). 

I have been looking on the internet at various representations of Unicode characters (OK, codepoints). It seems that there are some forms that include formatting information and some that don't. For example, choosing that old chestnut, Greek letter lower case pi, a search appears to reveal:

U+1D70B seems to represent it in italic (written in LC as 0x1D70B)
U+1D7B9 in sans-serif bold (written in LC as 0x1D7B9)

but

U+0x3C0 appears to be pi with the formatting ignored,

and finally I swear that some PDF I downloaded from the Unicode Consortium gave

U+1D77F as a legitimate representation of pi - (written 0x1D77F)

Sure enough, in the LC 7 message box, ALL these generate a pi glyph.

Can anyone explain what this means, and what I should do if someone pastes a Unicode string containing pi into my app - I mean how should I recognise it? Can I strip off the style info, and if so what is the rule for doing that?

If this happens for a little old symbol that we've all been using since childhood, what chance to we have with more exotic stuff?

Puzzled

Graham