diff --git a/src/lp/detail/field-decl.hpp b/src/lp/detail/field-decl.hpp
index 6804b8a..49e3c07 100644
--- a/src/lp/detail/field-decl.hpp
+++ b/src/lp/detail/field-decl.hpp
@@ -43,10 +43,6 @@
   BOOST_CONCEPT_REQUIRES(((WireDecodable<T>)), (T))
   decode(const Block& wire)
   {
-    if (wire.type() != TlvType::value) {
-      BOOST_THROW_EXCEPTION(ndn::tlv::Error("Unexpected TLV type " + to_string(wire.type())));
-    }
-
     T type;
     type.wireDecode(wire);
     return type;
@@ -59,10 +55,6 @@
   static uint64_t
   decode(const Block& wire)
   {
-    if (wire.type() != TlvType::value) {
-      BOOST_THROW_EXCEPTION(ndn::tlv::Error("Unexpected TLV type " + to_string(wire.type())));
-    }
-
     return readNonNegativeInteger(wire);
   }
 };
@@ -73,10 +65,6 @@
   static std::pair<Buffer::const_iterator, Buffer::const_iterator>
   decode(const Block& wire)
   {
-    if (wire.type() != TlvType::value) {
-      BOOST_THROW_EXCEPTION(ndn::tlv::Error("Unexpected TLV type " + to_string(wire.type())));
-    }
-
     if (wire.value_size() == 0) {
       BOOST_THROW_EXCEPTION(ndn::tlv::Error(to_string(wire.type()) + " must not be empty"));
     }
@@ -129,12 +117,23 @@
   typedef std::integral_constant<uint64_t, TYPE> TlvType;
   typedef std::integral_constant<bool, REPEATABLE> IsRepeatable;
 
+  /** \brief decodes a field
+   *  \param wire a Block with top-level type \p TYPE
+   *  \return value of the field
+   */
   static ValueType
   decode(const Block& wire)
   {
+    if (wire.type() != TlvType::value) {
+      BOOST_THROW_EXCEPTION(ndn::tlv::Error("Unexpected TLV type " + std::to_string(wire.type())));
+    }
+
     return DecodeHelper<TlvType, ValueType>::decode(wire);
   }
 
+  /** \brief encodes a field and prepends to \p encoder its Block with top-level type \p TYPE
+   *  \param value value of the field
+   */
   template<typename encoding::Tag TAG, typename T>
   static size_t
   encode(EncodingImpl<TAG>& encoder, const T& value)