Glacial Erratics

I've started reading Arnaud Leene's Microcontent Musings. An entry there provides a list of attributes that could lead to a definition of microcontent:    (PTY)

• small - read micro. This is still a troublesome attribute, as MicroContent? items seems to grow and grow and can become pretty large. But it is good to focus on smallness. MicroContent? can be small and that is worth to note in itself;    (PTZ)
• self-contained - this attribute I like much better. It means that MicroContent? can live on its own. It does not need to have context. I am not sure whether I exclude an MicroContent? types by this, such as Discussion Forum Items. In a Discussion Forum has a strong thread between each Item in a discussion;    (PU0)
• addressable - I think that this one is important. This is Marc Canter's demand. Each piece of MicroContent? must have a unique permaUri. That allows for syndication in all kind of forms. This implies that MicroContent? can be autonomous;    (PU1)
• structured - MicroContent? should have structure. This can be extremely minimal (title, permaUri, description), but ideally more fields are defined;    (PU2)
• flexibility - MicroContent? should not be rigid in it's structure. The user should be able to add fields at will, or fallback to a minimal set. Flexibility also implies that there shouldn't be any rigid schema's underlying any MicroContent? type. It should be like OPML, but with a good reference to a dictionary;    (PU3)
• single - this attribute I am not sure about. I believe that each MicroContent? item should have it's own file (or resource). There seems to be a trend to embed multiple MicroContent? items in a single piece of MacroContent?. If you see the number of different MicroContent? items (and types) people add to their blog-page, it has become a petri-dish for all kinds of MicroContent?. It will become harder and harder to extract the MicroContent? item you want. I am afraid this will hamper the creation of the MicroWeb?;    (PU4)
• computer data - I reference this in my definition, so I should include it here as well: we talk about computer readable data;    (PU5)

The long term vision for PurpleNumbers is for them to be the identifiers for addressable, self-contained, small, flexible, single chunks of computer data that are usable alone or can be composed into more complex structures (documents).    (PU6)