This weekend’s papers have brought up (quite inadvertently on their part) a problem caused by the development of non-rhotic accents:
“High Street banks are often reluctant to invest in what they see as risky and uncharted territory” (Mail on Sunday, 24 June 2012)
“We’re in somewhat unchartered territory in 2020.” (The Independent, 23 June 2012).
My non-rhotic pronunciation is such that I could never confuse these two words: (un)charted /ˈtʃɑːtɪd/ versus (un)chartered /ˈtʃɑːtəd/. But the version of non-rhotic English espoused notably by Tony Blair, but also by many others, uses schwa in both words (/ˈtʃɑːtəd/), leading to the mis-use of ‘(un)chartered’ for ‘(un)charted’ in such contexts.
A similar problem arises with formerly and formally.
“The artist /ˈfɔːməli/ known as Prince” could be interpreted as either, with totally different meanings. Prince intends, and as a rhotic American, spells, formerly, but if “Prince” was his official name, then formally would be equally appropriate.
I don’t believe that any amount of spelling reform could eliminate this problem.