diff --git a/object/service.proto b/object/service.proto
index 2119e7a..c55e21d 100644
--- a/object/service.proto
+++ b/object/service.proto
@@ -20,17 +20,6 @@ service ObjectService {
   // be restored by concatenation of object message payload and all chunks
   // keeping the receiving order.
   //
-  // Extended headers can change `Get` behaviour:
-  // * __NEOFS__NETMAP_EPOCH \
-  //   Will use the requsted version of Network Map for object placement
-  //   calculation.
-  // * __NEOFS__NETMAP_LOOKUP_DEPTH \
-  //   Will try older versions (starting from `__NEOFS__NETMAP_EPOCH` if specified or
-  //   the latest one otherwise) of Network Map to find an object until the depth
-  //   limit is reached.
-  //
-  // Please refer to detailed `XHeader` description.
-  //
   // Statuses:
   // - **OK** (0, SECTION_SUCCESS): \
   //   object has been successfully read;
@@ -54,13 +43,6 @@ service ObjectService {
   // object payload. All messages, except first one, SHOULD be payload chunks.
   // Chunk messages SHOULD be sent in the direct order of fragmentation.
   //
-  // Extended headers can change `Put` behaviour:
-  // * __NEOFS__NETMAP_EPOCH \
-  //   Will use the requsted version of Network Map for object placement
-  //   calculation.
-  //
-  // Please refer to detailed `XHeader` description.
-  //
   // Statuses:
   // - **OK** (0, SECTION_SUCCESS): \
   //   object has been successfully saved in the container;
@@ -161,16 +143,6 @@ service ObjectService {
   // restored by concatenation of all received payload chunks keeping the receiving
   // order.
   //
-  // Extended headers can change `GetRange` behaviour:
-  // * __NEOFS__NETMAP_EPOCH \
-  //   Will use the requsted version of Network Map for object placement
-  //   calculation.
-  // * __NEOFS__NETMAP_LOOKUP_DEPTH \
-  //   Will try older versions of Network Map to find an object until the depth
-  //   limit is reached.
-  //
-  // Please refer to detailed `XHeader` description.
-  //
   // Statuses:
   // - **OK** (0, SECTION_SUCCESS): \
   //   data range of the object payload has been successfully read;
@@ -194,16 +166,6 @@ service ObjectService {
   // length) tuples. Hashes order in response corresponds to the ranges order in
   // the request. Note that hash is calculated for XORed data.
   //
-  // Extended headers can change `GetRangeHash` behaviour:
-  // * __NEOFS__NETMAP_EPOCH \
-  //   Will use the requsted version of Network Map for object placement
-  //   calculation.
-  // * __NEOFS__NETMAP_LOOKUP_DEPTH \
-  //   Will try older versions of Network Map to find an object until the depth
-  //   limit is reached.
-  //
-  // Please refer to detailed `XHeader` description.
-  //
   // Statuses:
   // - **OK** (0, SECTION_SUCCESS): \
   //   data range of the object payload has been successfully hashed;
diff --git a/proto-docs/object.md b/proto-docs/object.md
index 9ee7d17..e9b5230 100644
--- a/proto-docs/object.md
+++ b/proto-docs/object.md
@@ -95,17 +95,6 @@ messages, except the first one, carry payload chunks. The requested object can
 be restored by concatenation of object message payload and all chunks
 keeping the receiving order.
 
-Extended headers can change `Get` behaviour:
-* __NEOFS__NETMAP_EPOCH \
-  Will use the requsted version of Network Map for object placement
-  calculation.
-* __NEOFS__NETMAP_LOOKUP_DEPTH \
-  Will try older versions (starting from `__NEOFS__NETMAP_EPOCH` if specified or
-  the latest one otherwise) of Network Map to find an object until the depth
-  limit is reached.
-
-Please refer to detailed `XHeader` description.
-
 Statuses:
 - **OK** (0, SECTION_SUCCESS): \
   object has been successfully read;
@@ -133,13 +122,6 @@ session package). Chunk messages are considered by server as a part of an
 object payload. All messages, except first one, SHOULD be payload chunks.
 Chunk messages SHOULD be sent in the direct order of fragmentation.
 
-Extended headers can change `Put` behaviour:
-* __NEOFS__NETMAP_EPOCH \
-  Will use the requsted version of Network Map for object placement
-  calculation.
-
-Please refer to detailed `XHeader` description.
-
 Statuses:
 - **OK** (0, SECTION_SUCCESS): \
   object has been successfully saved in the container;
@@ -256,16 +238,6 @@ Like in `Get` method, the response uses gRPC stream. Requested range can be
 restored by concatenation of all received payload chunks keeping the receiving
 order.
 
-Extended headers can change `GetRange` behaviour:
-* __NEOFS__NETMAP_EPOCH \
-  Will use the requsted version of Network Map for object placement
-  calculation.
-* __NEOFS__NETMAP_LOOKUP_DEPTH \
-  Will try older versions of Network Map to find an object until the depth
-  limit is reached.
-
-Please refer to detailed `XHeader` description.
-
 Statuses:
 - **OK** (0, SECTION_SUCCESS): \
   data range of the object payload has been successfully read;
@@ -293,16 +265,6 @@ applying XOR operation with the provided `salt`. Ranges are set of (offset,
 length) tuples. Hashes order in response corresponds to the ranges order in
 the request. Note that hash is calculated for XORed data.
 
-Extended headers can change `GetRangeHash` behaviour:
-* __NEOFS__NETMAP_EPOCH \
-  Will use the requsted version of Network Map for object placement
-  calculation.
-* __NEOFS__NETMAP_LOOKUP_DEPTH \
-  Will try older versions of Network Map to find an object until the depth
-  limit is reached.
-
-Please refer to detailed `XHeader` description.
-
 Statuses:
 - **OK** (0, SECTION_SUCCESS): \
   data range of the object payload has been successfully hashed;
diff --git a/proto-docs/session.md b/proto-docs/session.md
index 2cdfd1e..7fa1629 100644
--- a/proto-docs/session.md
+++ b/proto-docs/session.md
@@ -285,18 +285,8 @@ Key name must be a unique valid UTF-8 string. Value can't be empty. Requests or
 Responses with duplicated header names or headers with empty values will be
 considered invalid.
 
-There are some "well-known" headers starting with `__NEOFS__` prefix that
-affect system behaviour:
-
-* __NEOFS__NETMAP_EPOCH \
-  Netmap epoch to use for object placement calculation. The `value` is string
-  encoded `uint64` in decimal presentation. If set to '0' or not set, the
-  current epoch only will be used.
-* __NEOFS__NETMAP_LOOKUP_DEPTH \
-  If object can't be found using current epoch's netmap, this header limits
-  how many past epochs the node can look up through. The `value` is string
-  encoded `uint64` in decimal presentation. If set to '0' or not set, only the
-  current epoch will be used.
+Headers with `__NEOFS__` prefix are reserved for system needs, regular clients
+should avoid using them.
 
 
 | Field | Type | Label | Description |
diff --git a/session/types.proto b/session/types.proto
index d00e99f..3e8b598 100644
--- a/session/types.proto
+++ b/session/types.proto
@@ -137,18 +137,8 @@ message SessionToken {
 // Responses with duplicated header names or headers with empty values will be
 // considered invalid.
 //
-// There are some "well-known" headers starting with `__NEOFS__` prefix that
-// affect system behaviour:
-//
-// * __NEOFS__NETMAP_EPOCH \
-//   Netmap epoch to use for object placement calculation. The `value` is string
-//   encoded `uint64` in decimal presentation. If set to '0' or not set, the
-//   current epoch only will be used.
-// * __NEOFS__NETMAP_LOOKUP_DEPTH \
-//   If object can't be found using current epoch's netmap, this header limits
-//   how many past epochs the node can look up through. The `value` is string
-//   encoded `uint64` in decimal presentation. If set to '0' or not set, only the
-//   current epoch will be used.
+// Headers with `__NEOFS__` prefix are reserved for system needs, regular clients
+// should avoid using them.
 message XHeader {
   // Key of the X-Header
   string key = 1 [json_name = "key"];