diff --git a/alliance/share/man/man5/spi.5 b/alliance/share/man/man5/spi.5
index 41d4c770..554e165b 100644
--- a/alliance/share/man/man5/spi.5
+++ b/alliance/share/man/man5/spi.5
@@ -89,6 +89,8 @@ Environment variable considered are
 .B MBK_SPI_VERBOSE
 
 .B MBK_SPI_ONE_NODE_NORC
+
+.B MBK_SPI_NO_AFF_UNK
 .RE
 
 .SH ENVIRONMENT VARIABLES
@@ -127,6 +129,10 @@ If this variable is set, display debug various information on the error output.
 
 If this variable is set, an RCN view is not created for a net containing only one node.
 
+.B MBK_SPI_NO_AFF_UNK
+
+Default behaviour of Spice parser is to display an error message when an unknown element is read in the input file. Setting this variable prevent this display. Usefull when file contain command for Spice simulator.
+
 .SH EXAMPLE
 
 This is an example of a file generated by the Spice driver.