diff --git a/docs/DATA_FORMATS_INPUT.md b/docs/DATA_FORMATS_INPUT.md
index 96dd111b7..b79a182be 100644
--- a/docs/DATA_FORMATS_INPUT.md
+++ b/docs/DATA_FORMATS_INPUT.md
@@ -657,6 +657,73 @@ For more information about the dropwizard json format see
 #### Grok
 Parse logstash-style "grok" patterns. Patterns can be added to patterns, or custom patterns read from custom_pattern_files.
 
+# View logstash grok pattern docs here:
+#   https://www.elastic.co/guide/en/logstash/current/plugins-filters-grok.html
+# All default logstash patterns are supported, these can be viewed here:
+#   https://github.com/logstash-plugins/logstash-patterns-core/blob/master/patterns/grok-patterns
+
+# Available modifiers:
+#   string   (default if nothing is specified)
+#   int
+#   float
+#   duration (ie, 5.23ms gets converted to int nanoseconds)
+#   tag      (converts the field into a tag)
+#   drop     (drops the field completely)
+# Timestamp modifiers:
+#   ts-ansic         ("Mon Jan _2 15:04:05 2006")
+#   ts-unix          ("Mon Jan _2 15:04:05 MST 2006")
+#   ts-ruby          ("Mon Jan 02 15:04:05 -0700 2006")
+#   ts-rfc822        ("02 Jan 06 15:04 MST")
+#   ts-rfc822z       ("02 Jan 06 15:04 -0700")
+#   ts-rfc850        ("Monday, 02-Jan-06 15:04:05 MST")
+#   ts-rfc1123       ("Mon, 02 Jan 2006 15:04:05 MST")
+#   ts-rfc1123z      ("Mon, 02 Jan 2006 15:04:05 -0700")
+#   ts-rfc3339       ("2006-01-02T15:04:05Z07:00")
+#   ts-rfc3339nano   ("2006-01-02T15:04:05.999999999Z07:00")
+#   ts-httpd         ("02/Jan/2006:15:04:05 -0700")
+#   ts-epoch         (seconds since unix epoch)
+#   ts-epochnano     (nanoseconds since unix epoch)
+#   ts-"CUSTOM"
+# CUSTOM time layouts must be within quotes and be the representation of the
+# "reference time", which is Mon Jan 2 15:04:05 -0700 MST 2006
+# See https://golang.org/pkg/time/#Parse for more details.
+
+# Example log file pattern, example log looks like this:
+#   [04/Jun/2016:12:41:45 +0100] 1.25 200 192.168.1.1 5.432µs
+# Breakdown of the DURATION pattern below:
+#   NUMBER  is a builtin logstash grok pattern matching float & int numbers.
+#   [nuµm]? is a regex specifying 0 or 1 of the characters within brackets.
+#   s       is also regex, this pattern must end in "s".
+# so DURATION will match something like '5.324ms' or '6.1µs' or '10s'
+DURATION %{NUMBER}[nuµm]?s
+RESPONSE_CODE %{NUMBER:response_code:tag}
+RESPONSE_TIME %{DURATION:response_time_ns:duration}
+EXAMPLE_LOG \[%{HTTPDATE:ts:ts-httpd}\] %{NUMBER:myfloat:float} %{RESPONSE_CODE} %{IPORHOST:clientip} %{RESPONSE_TIME}
+
+# Wider-ranging username matching vs. logstash built-in %{USER}
+NGUSERNAME [a-zA-Z0-9\.\@\-\+_%]+
+NGUSER %{NGUSERNAME}
+# Wider-ranging client IP matching
+CLIENT (?:%{IPORHOST}|%{HOSTPORT}|::1)
+
+##
+## COMMON LOG PATTERNS
+##
+
+# apache & nginx logs, this is also known as the "common log format"
+#   see https://en.wikipedia.org/wiki/Common_Log_Format
+COMMON_LOG_FORMAT %{CLIENT:client_ip} %{NOTSPACE:ident} %{NOTSPACE:auth} \[%{HTTPDATE:ts:ts-httpd}\] "(?:%{WORD:verb:tag} %{NOTSPACE:request}(?: HTTP/%{NUMBER:http_version:float})?|%{DATA})" %{NUMBER:resp_code:tag} (?:%{NUMBER:resp_bytes:int}|-)
+
+# Combined log format is the same as the common log format but with the addition
+# of two quoted strings at the end for "referrer" and "agent"
+#   See Examples at http://httpd.apache.org/docs/current/mod/mod_log_config.html
+COMBINED_LOG_FORMAT %{COMMON_LOG_FORMAT} %{QS:referrer} %{QS:agent}
+
+# HTTPD log formats
+HTTPD20_ERRORLOG \[%{HTTPDERROR_DATE:timestamp}\] \[%{LOGLEVEL:loglevel:tag}\] (?:\[client %{IPORHOST:clientip}\] ){0,1}%{GREEDYDATA:errormsg}
+HTTPD24_ERRORLOG \[%{HTTPDERROR_DATE:timestamp}\] \[%{WORD:module}:%{LOGLEVEL:loglevel:tag}\] \[pid %{POSINT:pid:int}:tid %{NUMBER:tid:int}\]( \(%{POSINT:proxy_errorcode:int}\)%{DATA:proxy_errormessage}:)?( \[client %{IPORHOST:client}:%{POSINT:clientport}\])? %{DATA:errorcode}: %{GREEDYDATA:message}
+HTTPD_ERRORLOG %{HTTPD20_ERRORLOG}|%{HTTPD24_ERRORLOG}
+
 #### Grok Configuration:
 ```toml
   [inputs.reader]
diff --git a/plugins/inputs/reader/README.md b/plugins/inputs/reader/README.md
index 190bdb1f5..39adb253d 100644
--- a/plugins/inputs/reader/README.md
+++ b/plugins/inputs/reader/README.md
@@ -1,10 +1,12 @@
 # Reader Input Plugin
 
-The Reader Plugin updates a list of files every interval and parses the data inside.  
+The Reader Plugin updates a list of files every interval and parses the data inside.
+Files will always be read from the beginning.  
 This plugin can parse any "data_format" formats.
 
 ### Configuration:
 ```toml
+[[inputs.reader]]
 ## Files to parse each interval.
 ## These accept standard unix glob matching rules, but with the addition of
 ## ** as a "super asterisk". ie: