comparison on password book formats

After failing to find a fast, feature-rich user-friendly opensource password manager I start to think of writing my own. I don't want to invent a new file format, because it's labour also because it's reinventing the wheel. This comparison serve a base as I start my work on my own password manager.

Comparision of lightweight web servers
Features	basic feature?¹	Revelation	gpass 0.5
not depending on application²	Yes	?
Well documented and stable	Yes	?
stores password description and name in unicode or user's preferred locale	Yes	Yes
contain hierarchy²	Yes	Yes	Yes
content different types of passwords	Yes	Yes
contain password templates for each password type	Yes	No
include icon bitmap in password template	No	No
contain search index	No	?
free from database engine requirements (e.g. sqlite) for accessing it	No	Yes
file format accessible with text editor	No	No
embed certificate files	No	No
embed key files	No	No
can encrypte differnt parts of the file with different password/key³	No	No
can hold password entry atime/ctime	No	?	Yes
contain date format (for expiration date)	No	?	Yes

Basic feature means the feature I personally think should be considered mandantory requirement for any acceptable format.
The file format should not be a dump of memory structure of the application (e.g. hsqlprefs.dat by HSQL is a Java serialized object). It should be general, not specific to a programming language or an application.
Hierarchy allows store password by area ("business") then by customer ("Johnson & Johnson") then by project ("internal contact db") then by server ("primary web") then by service .... I think being able to group passwords, a.k.a. having only 2 levels, should be enough for more than half users.
for shared password book or for multi-level-security password book

There are enough people start a software project by writing it instead of thinking it. I don't want to make a project like that. That's why I have this comparison.