How to define attributes and functions on an <<interface>>?

[Martin John Bramwell]

I have read the post "Error drawing Interface with class members, just draws "N".

// Using FULLWIDTH LESS-THAN SIGN and FULLWIDTH GREATER-THAN SIGN

[＜＜Interface＞＞ Asset|qrCode:varchar|order(int)]^-.-[Ununoctium]

When I try to use the suggested characters, they all appear as empty box characters.

I was successful using the french quotation characters  «   and   »   

// Using Guillemet

[«Interface» Asset|qrCode:varchar|order(int)]^-.-[Space Station]

[«Interface» Asset]^-.-[Paper Clip]

From http://www.cs.tut.fi/~jkorpela/html/french.html . . . 

Glyph  Common name     Windows      Reference     Unicode
  «    left guillemet  0171       &laquo;      00AB
  »    right guillemet 0187       &raquo;      00BB