diff --git a/doc/example-config/conf.d/90-sieve.conf b/doc/example-config/conf.d/90-sieve.conf
index 238bcf46a46963822ec25c28f797ac9e04f02d95..532a77645c423e1a650939da0e12fd390e75cf1b 100644
--- a/doc/example-config/conf.d/90-sieve.conf
+++ b/doc/example-config/conf.d/90-sieve.conf
@@ -86,13 +86,13 @@ plugin {
 
   # Which Sieve language extensions are available to users. By default, all
   # supported extensions are available, except for deprecated extensions or
-  # those that are still under development. Some system administrators may want
-  # to disable certain Sieve extensions or enable those that are not available
-  # by default. This setting can use '+' and '-' to specify differences relative
-  # to the default. For example `sieve_extensions = +imapflags' will enable the
-  # deprecated imapflags extension in addition to all extensions were already
-  # enabled by default.
-  #sieve_extensions = +notify +imapflags
+  # those that can be dangerous or are still under development. Some system
+  # administrators may want to disable certain Sieve extensions or enable those
+  # that are not available by default. This setting can use '+' and '-' to
+  # specify differences relative to the default. For example
+  # `sieve_extensions = +editheader' will enable the editheader extension in
+  # addition to all extensions were already enabled by default.
+  #sieve_extensions = +editheader
 
   # Which Sieve language extensions are ONLY available in global scripts. This
   # can be used to restrict the use of certain Sieve extensions to administrator
diff --git a/doc/extensions/duplicate.txt b/doc/extensions/duplicate.txt
index 962e69e8da0f359f25e5c9aedc269e0a15bde1da..1c815a817b19b9c7ad26ee79c0421690c35d028c 100644
--- a/doc/extensions/duplicate.txt
+++ b/doc/extensions/duplicate.txt
@@ -18,10 +18,7 @@ IDs from previously delivered messages.  For more complex applications, the
 parts of the message.
 
 Refer to doc/rfc/duplicate.rfc7352.txt for a specification of the Sieve language
-extension. Previously, this extension was Dovecot-specific and available under
-the name "vnd.dovecot.duplicate". That implementation differs significantly from
-what is now published as an RFC, but for backwards compatibility the original
-extension is still supported.
+extension.
 
 Configuration
 =============
diff --git a/doc/man/sieve-dump.1.in b/doc/man/sieve-dump.1.in
index 7a79c6824474a87fbbb02aff742ee454e90380cb..f9e23aa201469fc8452a970700c95081363dce7d 100644
--- a/doc/man/sieve-dump.1.in
+++ b/doc/man/sieve-dump.1.in
@@ -71,9 +71,9 @@ of active extensions. If no extensions have a \fB+\fP or \fB\-\fP prefix, only
 those extensions that are explicitly listed will be enabled. Unknown extensions
 are ignored and a warning is produced.
 
-For example \fB\-x\fP \(dq+imapflags \-enotify\(dq will enable the deprecated
-imapflags extension and disable the enotify extension. The rest of the active
-extensions depends on the \fIsieve_extensions\fP and
+For example \fB\-x\fP \(dq+editheader \-enotify\(dq will enable the editheader
+extension and disable the enotify extension. The rest of the active extensions
+depends on the \fIsieve_extensions\fP and
 \fIsieve_global_extensions\fP settings. By default, i.e.
 when \fIsieve_extensions\fP and \fIsieve_global_extensions\fP remain
 unconfigured, all supported extensions are available, except for deprecated
diff --git a/doc/man/sieve-filter.1.in b/doc/man/sieve-filter.1.in
index 1ce804b61c967b3f4cae04aa5ef7a4d9b73107de..79ea11aa63e3cd90a310a0cb5fcdf268ef9e3aea 100644
--- a/doc/man/sieve-filter.1.in
+++ b/doc/man/sieve-filter.1.in
@@ -147,9 +147,9 @@ of active extensions. If no extensions have a \fB+\fP or \fB\-\fP prefix, only
 those extensions that are explicitly listed will be enabled. Unknown extensions
 are ignored and a warning is produced.
 
-For example \fB\-x\fP \(dq+imapflags \-enotify\(dq will enable the deprecated
-imapflags extension and disable the enotify extension. The rest of the active
-extensions depends on the \fIsieve_extensions\fP and
+For example \fB\-x\fP \(dq+editheader \-enotify\(dq will enable the editheader
+extension and disable the enotify extension. The rest of the active extensions
+depends on the \fIsieve_extensions\fP and
 \fIsieve_global_extensions\fP settings. By default, i.e.
 when \fIsieve_extensions\fP and \fIsieve_global_extensions\fP remain
 unconfigured, all supported extensions are available, except for deprecated
diff --git a/doc/man/sieve-test.1.in b/doc/man/sieve-test.1.in
index 65e5230dd08c31985c510da1ed8bfdb047f81446..c7d6bd4ccf53aebfaafacd00dcb3c1cb7d34b41d 100644
--- a/doc/man/sieve-test.1.in
+++ b/doc/man/sieve-test.1.in
@@ -133,9 +133,9 @@ of active extensions. If no extensions have a \fB+\fP or \fB\-\fP prefix, only
 those extensions that are explicitly listed will be enabled. Unknown extensions
 are ignored and a warning is produced.
 
-For example \fB\-x\fP \(dq+imapflags \-enotify\(dq will enable the deprecated
-imapflags extension and disable the enotify extension. The rest of the active
-extensions depends on the \fIsieve_extensions\fP and
+For example \fB\-x\fP \(dq+editheader \-enotify\(dq will enable the editheader
+extension and disable the enotify extension. The rest of the active extensions
+depends on the \fIsieve_extensions\fP and
 \fIsieve_global_extensions\fP settings. By default, i.e.
 when \fIsieve_extensions\fP and \fIsieve_global_extensions\fP remain
 unconfigured, all supported extensions are available, except for deprecated
diff --git a/doc/man/sievec.1.in b/doc/man/sievec.1.in
index 548bcca0cf4fda0c705570bebbff87feeea525f6..74aae05c4333afc98b324d547eb75b7c4cfeb07d 100644
--- a/doc/man/sievec.1.in
+++ b/doc/man/sievec.1.in
@@ -84,9 +84,9 @@ of active extensions. If no extensions have a \fB+\fP or \fB\-\fP prefix, only
 those extensions that are explicitly listed will be enabled. Unknown extensions
 are ignored and a warning is produced.
 
-For example \fB\-x\fP \(dq+imapflags \-enotify\(dq will enable the deprecated
-imapflags extension and disable the enotify extension. The rest of the active
-extensions depends on the \fIsieve_extensions\fP and
+For example \fB\-x\fP \(dq+editheader \-enotify\(dq will enable the editheader
+extension and disable the enotify extension. The rest of the active extensions
+depends on the \fIsieve_extensions\fP and
 \fIsieve_global_extensions\fP settings. By default, i.e.
 when \fIsieve_extensions\fP and \fIsieve_global_extensions\fP remain
 unconfigured, all supported extensions are available, except for deprecated