+.I PASSWORD_STORE_GENERATED_LENGTH
+The default password length if the \fIpass-length\fP parameter to \fBgenerate\fP
+is unspecified.
+.TP
+.I PASSWORD_STORE_CHARACTER_SET
+The character set to be used in password generation for \fBgenerate\fP. This value
+is to be interpreted by \fBtr\fP. See
+.BR tr (1)
+for more info.
+.TP
+.I PASSWORD_STORE_CHARACTER_SET_NO_SYMBOLS
+The character set to be used in no-symbol password generation for \fBgenerate\fP,
+when \fI--no-symbols\fP, \fI-n\fP is specified. This value is to be interpreted
+by \fBtr\fP. See
+.BR tr (1)
+for more info.
+.TP
+.I PASSWORD_STORE_ENABLE_EXTENSIONS
+This environment variable must be set to "true" for extensions to be enabled.
+.TP
+.I PASSWORD_STORE_EXTENSIONS_DIR
+The location to look for executable extension files, by default
+\fIPASSWORD_STORE_DIR/.extensions\fP.
+.TP
+.I PASSWORD_STORE_SIGNING_KEY
+If this environment variable is set, then all \fB.gpg-id\fP files and non-system extension files
+must be signed using a detached signature using the GPG key specified by the full 40 character
+upper-case fingerprint in this variable. If multiple fingerprints are specified, each
+separated by a whitespace character, then signatures must match at least one.
+The \fBinit\fP command will keep signatures of \fB.gpg-id\fP files up to date.
+.TP