You need to find the file where you put your entry and delete the entry, the same way you delete a sentence in the text, not more complicated than that.
Since all entries are kept in plain text, it's also easy to modify an entry's coordinates, name and such, doesn't require any specific knowledge but normal text editing skills and any plain text editor like Notepad.
Due to the fact that you are in control of your data, and you can split information into files any way you like, on public/private basic, or hunt-wise or soc-wise ... also due to the fact that you can add/delete/modify data files on the fly without restarting oceanic - currently there is no way to do it automatically, creating such an editor is a huge job.
If you use a common format to keep your own records, like CSV, you can make your data compatible with Little Big Mining Log CSV format, since it's a pretty general one.
Oceanic can convert LBML files into it's own format through a special tool called
Oceanic Importer
There are a couple of real LBML files supplied with Oceanic, so you can use them to see how it all works. The conversion is fully automated.
Alternatively, if you use your own uncommon format, you can post a request to add a new converter to OI
here
Each type of resource like Lyst or Oil can be turned on/off from the right side menu, where all resources and entries are displayed.
There are no layers in there, and there is no need to program them, but it works exactly as they would be on a separate layer.
Also you can turn on/off groups of entries like all Enmatter or Ore or Teleporters, in the same menu.
..on top of that, you can place any number of any resources of any type into a separate file and turn that file on/off.. still in the same right side menu, dynamically, w/o restarting oceanic.
You can find many examples of that in Arkadia data files supplied with Oceanic, that contains info about Arkadian mob spawns.
Since you can add any number of different attributes to any entry, it's not easy to build an editor for that, so if you unfamiliar with XML, you can just find an example once and then reuse it as many times as you need.
In you don't need any extensive comments, a spawn entry for Oceanic will look like this:
<entry type="Otorugi" Levels="26-40" Maturities="Young,Old" Mood="Happy" Appetite="Excellent" data="11789,31416:12879,31416:12879,30308:11789,30308:1" />
All attributes, like Maturities, Mood and Appetite will be displayed automatically in the oceanic info window once you click on the spawn.
There is also an extensive tutorial written for lay audience at
oceanic web site