Update documentation (#2808)

CHANGELOG.md

@@ -13,6 +13,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 ### Changed
 
 - Python 3.12 and later is now supported.
+- When exporting GAMS `.gdx` files with Exporter, special values 10<sup>-10</sup> and `EPS`
+  now get converted to GAMS Eps (epsilon).
 
 ### Deprecated
 

docs/source/data_import_export.rst

@@ -443,6 +443,16 @@ The gdx backend turns the output tables to GAMS sets, parameters and scalars fol
   Everything else (except the table name) is ignored.
 * The data in the top left cell is the scalar's value.
 
+The following conversions are done for GAMS special values:
+
+==================  ====================================================
+GAMS special value  Original value
+==================  ====================================================
++Inf                IEEE 754 infinity
+-Inf                Negative IEEE 754 infinity
+Eps                 2.2250738585072014e-308, 1e-10 or the string ``EPS``
+==================  ====================================================
+
 .. _Basic regular expressions for filtering:
 
 Basic regular expressions for filtering