I think it is the symbol of diameter. Well... I can: ∅ and ϕ
This are some details of phi:
UTF-8: 0xCF 0x95
UTF-16: 0x03D5
C-form (octal escaped UTF-8): \317\225
XML-form (decimal): ϕ
Symbols in linx http://img576.imageshack.us/img576/6153/symbolsinlinux.png