File Type Categories.txt
This customizable file defines of which file types categories are comprised. The name of a category is preceded by three asterisks and a space (*** ). Following is a list of file types that belong to that category, one per line. Such lines must start with either a "+" or a "-", where "+" simply means that type is checked in the file type filter. After that, typical extension for that file type follows, plus a space character, followed by a description of the file type. Only lower-case letters are to be used in extensions. The same file extension/type may occur in multiple categories (see Category column description for limitations).
Alternatively to extensions, entire filenames are supported as well. This is useful for certain files with a well-defined name whose extension alone is not specific enough or which do not have any extension. Complete filenames have to be enclosed in semicolons. Examples:
-;index.dat; Internet Explorer history/cache
-;history.dat; Mozilla/Firefox browser history
-;passwd; Existing users
There is a virtual "Other/Unknown type" category, which is not specifically defined in the file and simply covers all files that do not belong to any other, defined category.
You may store additional custom definitions of file types and categories in a separate file named "File Type Categories User.txt". This file will be read and maintained in addition to the standard definitions in "File Type Categories.txt" and has the same structure, but is not overwritten by updates of the software if contained in the installation directory, so that you can easily continue to use it even when overwriting your installation with a new version.
File types are ranked by importance/relevance and you may filter by this rank. For example, filtering out those file types ranked #0 will exclude font files, cursors, icons, themes, skins, clip arts, etc. Files with a low rank are of importance just in very specific investigations, for example source code, in which you would not be interested when looking for office documents or pictures for example, but definitely when hunting a virus programmer. Higher ranked file types are relevant in more cases. Generally the rank is useful in simple cases where you can expect to find what you are looking for in file types that are fairly well known. As another idea, you could make it a habit to only index files with higher ranks.
You also have the option to assign file types to a so-called group, a concept that is not identical to a file type category. Useful for example if your standard procedure is to let examiner A check out pictures and videos, examiner B documents, e-mail, and other Internet activity, and examiner C operating system files of various kinds, because of their specializations. You can give these groups meaningful names and filter for them, also using the Type Status dialog window. The groups are displayed in the Type filter.
All the definitions about file type ranks and file type groups are made in the "File Type Categories.txt" file. Suggestions for ranks and an example of a group of files that may deserve special attention are already predefined. Both ranks (from 0 to 9, where missing means 0) and groups (letters from A to Z) can be optionally specified following a tab at the end of a line, in any order, for example as "2P" or "DI3". So up to 10 rank levels are possible, but it is not necessary to fully utilize this range. Up to 26 groups are possible. You do not have to start alphabetically. The case of the letters is ignored. You may also define ranks and groups for an entire category, following a tab in a category line. File types that have no rank and category inherit both from the category to which they belong.
To give a group a more descriptive name than just a single letter, insert group definition lines at the end of the text file that start with a equal sign, e.g.
=P=Photos and videos for image group
=D=Docs, e-mails and Internet
=I=File types to index
You may store additional custom definitions of file types and categories in a separate file named "File Type Categories User.txt", which will be read and maintained in addition to the standard definitions in "File Type Categories.txt" and has the same structure and is not overwritten by updates of the software if contained in the installation directory, so that you can easily continue to use it even when overwriting your installation with a new version.