This package provides the following PostgreSQL modules:
  - citext
  - hstore
  - intarray
  - isn
  - ltree
  - lo
  - uuid-ossp
  - unaccent

The "citext" module provides a case-insensitive character string type,
citext. Essentially, it internally calls lower when comparing values.
Otherwise, it behaves almost exactly like text.

The "hstore" module implements the "hstore" data type for storing sets
of key/value pairs within a single PostgreSQL value. This can be useful
in various scenarios, such as rows with many attributes that are rarely
examined, or semi-structured data. Keys and values are simply text strings.

The "intarray" module provides a number of useful functions and operators
for manipulating one-dimensional arrays of integers. There is also support
for indexed searches using some of the operators.

The "isn" module provides data types for the following international
product numbering standards: EAN13, UPC, ISBN (books), ISMN (music),
and ISSN (serials). Numbers are validated on input, and correctly
hyphenated on output.

The "ltree" module implements a data type ltree for representing
labels of data stored in a hierarchical tree-like structure.
Extensive facilities for searching through label trees are provided.

The "lo" module provides support for managing Large Objects (also called
LOs or BLOBs). This includes a data type "lo" and a trigger "lo_manage."

The "uuid-ossp" module provides functions to generate universally unique
identifiers (UUIDs) using one of several standard algorithms. There are
also functions to produce certain special UUID constants.

"unaccent" is a text search dictionary that removes accents (diacritic signs)
from lexemes. It's a filtering dictionary, which means its output is always
passed to the next dictionary (if any), unlike the normal behavior of
dictionaries. This allows accent-insensitive processing for full text search.