why? what's wrong with customizable indicators for different ranks?
It would make seeing peoples ranks easier without clicking the guild. And you would only see the icon of people with the same tag as you if you are both on the same tag.
It would be great for towers. You can see a leader indicator, a permanent recruiter indicator.
For a spar guild you could utilize it for your own rank system so there is a set chain of command.
Or even ONTOP of a command system you can use it to have a 'GST prospects' rank to let your members know which ones are actually being considered for the GST team via indicator and if you aren't one of those prospects and you want to be, you can work harder to get that rank.
For any styled guild you can utilize ranks to make people want to do better in the guild.
PK guilds like (Guild B) can rank its members off of PK's per week and activity to encourage members to try harder.
Guilds like Zanza (who probably has the oldest and most used ranking system on iclassic, could see which rank every member is just by the indicator.