Lexicographic capitalization

I've noticed that there are considerable differences in capitalization of proprietary words in various dictionaries and am wondering if this depends mostly on diifferent trademark situations that might exist in different countries: Take the follwing examples:
c=cap nc=non cap c+nc- both cap and non cap
Cdn Oxford OED Encarta
1-aspirin c nc nc
2-cellophane c c+nc nc
3-saran nc c nc
4-realtor nc c c
5=laundromat nc c c
Anyone?