diff --git a/doc/api/dgram.md b/doc/api/dgram.md
index 0aa6a67668c32b..e44bf3eea5a166 100644
--- a/doc/api/dgram.md
+++ b/doc/api/dgram.md
@@ -161,7 +161,7 @@ added: v0.11.14
 -->
 
 * `options` {Object} Required. Supports the following properties:
-  * `port` {Integer}
+  * `port` {integer}
   * `address` {string}
   * `exclusive` {boolean}
 * `callback` {Function}
@@ -390,7 +390,7 @@ packets may be sent to a local interface's broadcast address.
 added: v8.6.0
 -->
 
-* `multicastInterface` {String}
+* `multicastInterface` {string}
 
 *Note: All references to scope in this section are referring to
 [IPv6 Zone Indices][], which are defined by [RFC 4007][]. In string form, an IP
diff --git a/doc/api/fs.md b/doc/api/fs.md
index e1dabde956c9d1..f2430b0da09a78 100644
--- a/doc/api/fs.md
+++ b/doc/api/fs.md
@@ -1334,7 +1334,7 @@ deprecated: v1.0.0
 
 * `path` {string|Buffer|URL}
 * `callback` {Function}
-  * `exists` {Boolean}
+  * `exists` {boolean}
 
 Test whether or not the given path exists by checking with the file system.
 Then call the `callback` argument with either true or false.  Example:
diff --git a/doc/api/net.md b/doc/api/net.md
index 03ed3d5cbc3955..b213829ffd3776 100644
--- a/doc/api/net.md
+++ b/doc/api/net.md
@@ -281,7 +281,7 @@ server.listen({
 added: v0.1.90
 -->
 
-* `path` {String} Path the server should listen to. See
+* `path` {string} Path the server should listen to. See
   [Identifying paths for IPC connections][].
 * `backlog` {number} Common parameter of [`server.listen()`][] functions.
 * `callback` {Function} Common parameter of [`server.listen()`][] functions.
diff --git a/doc/guides/using-internal-errors.md b/doc/guides/using-internal-errors.md
index 3ae11e901a62ba..90962757bb0bb2 100644
--- a/doc/guides/using-internal-errors.md
+++ b/doc/guides/using-internal-errors.md
@@ -119,8 +119,8 @@ likely be required.
 
 ### Class: errors.Error(key[, args...])
 
-* `key` {String} The static error identifier
-* `args...` {Any} Zero or more optional arguments
+* `key` {string} The static error identifier
+* `args...` {any} Zero or more optional arguments
 
 ```js
 const errors = require('internal/errors');
@@ -139,8 +139,8 @@ The `myError` object will have a `code` property equal to the `key` and a
 
 ### Class: errors.TypeError(key[, args...])
 
-* `key` {String} The static error identifier
-* `args...` {Any} Zero or more optional arguments
+* `key` {string} The static error identifier
+* `args...` {any} Zero or more optional arguments
 
 ```js
 const errors = require('internal/errors');
@@ -159,8 +159,8 @@ The `myError` object will have a `code` property equal to the `key` and a
 
 ### Class: errors.RangeError(key[, args...])
 
-* `key` {String} The static error identifier
-* `args...` {Any} Zero or more optional arguments
+* `key` {string} The static error identifier
+* `args...` {any} Zero or more optional arguments
 
 ```js
 const errors = require('internal/errors');
@@ -179,8 +179,8 @@ The `myError` object will have a `code` property equal to the `key` and a
 
 ### Method: errors.message(key, args)
 
-* `key` {String} The static error identifier
+* `key` {string} The static error identifier
 * `args` {Array} Zero or more optional arguments passed as an Array
-* Returns: {String}
+* Returns: {string}
 
 Returns the formatted error message string for the given `key`.