Uppercase acronym in comment

src/main/java/org/apache/commons/net/bsd/RCommandClient.java

@@ -35,8 +35,8 @@
  * without issuing a password. The trust relationship between two machines is established by the contents of a machine's /etc/hosts.equiv file and a user's
  * .rhosts file. These files specify from which hosts and accounts on those hosts rcmd() requests will be accepted. The only additional measure for establishing
  * trust is that all client connections must originate from a port between 512 and 1023. Consequently, there is an upper limit to the number of rcmd connections
- * that can be running simultaneously. The required ports are reserved ports on Unix systems, and can only be bound by a process running with root permissions
- * (to accomplish this rsh, rlogin, and related commands usualy have the suid bit set). Therefore, on a Unix system, you will only be able to successfully use
+ * that can be running simultaneously. The required ports are reserved ports on UNIX systems, and can only be bound by a process running with root permissions
+ * (to accomplish this rsh, rlogin, and related commands usualy have the suid bit set). Therefore, on a UNIX system, you will only be able to successfully use
  * the RCommandClient class if the process runs as root. However, there is no such restriction on Windows95 and some other systems. The security risks are
  * obvious. However, when carefully used, rcmd() can be very useful when used behind a firewall.
  * <p>

src/main/java/org/apache/commons/net/bsd/RExecClient.java

@@ -29,7 +29,7 @@
 import org.apache.commons.net.util.NetConstants;
 
 /**
- * RExecClient implements the rexec() facility that first appeared in 4.2BSD Unix. This class will probably only be of use for connecting to Unix systems and
+ * RExecClient implements the rexec() facility that first appeared in 4.2BSD Unix. This class will probably only be of use for connecting to UNIX systems and
  * only when the rexecd daemon is configured to run, which is a rarity these days because of the security risks involved. However, rexec() can be very useful
  * for performing administrative tasks on a network behind a firewall.
  * <p>

src/main/java/org/apache/commons/net/bsd/RLoginClient.java

@@ -45,7 +45,7 @@
 
 public class RLoginClient extends RCommandClient {
     /**
-     * The default rlogin port. Set to 513 in BSD Unix and according to RFC 1282.
+     * The default rlogin port. Set to 513 in BSD UNIX and according to RFC 1282.
      */
     public static final int DEFAULT_PORT = 513;
 

src/main/java/org/apache/commons/net/examples/nntp/ListNewsgroups.java

@@ -23,7 +23,7 @@
 import org.apache.commons.net.nntp.NewsgroupInfo;
 
 /**
- * This is a trivial example using the NNTP package to approximate the Unix newsgroups command. It merely connects to the specified news server and issues
+ * This is a trivial example using the NNTP package to approximate the UNIX newsgroups command. It merely connects to the specified news server and issues
  * fetches the list of newsgroups stored by the server. On servers that store a lot of newsgroups, this command can take a very long time (listing upwards of
  * 30,000 groups).
  */

src/main/java/org/apache/commons/net/examples/unix/finger.java

@@ -25,7 +25,7 @@
 
 /**
  * This is an example of how you would implement the finger command in Java using NetComponents. The Java version is much shorter. But keep in mind that the
- * Unix finger command reads all sorts of local files to output local finger information. This program only queries the finger daemon.
+ * UNIX finger command reads all sorts of local files to output local finger information. This program only queries the finger daemon.
  * <p>
  * The -l flag is used to request long output from the server.
  */

src/main/java/org/apache/commons/net/examples/unix/rdate.java

@@ -25,7 +25,7 @@
 import org.apache.commons.net.time.TimeUDPClient;
 
 /**
- * This is an example program demonstrating how to use the TimeTCPClient and TimeUDPClient classes. It's very similar to the simple Unix rdate command. This
+ * This is an example program demonstrating how to use the TimeTCPClient and TimeUDPClient classes. It's very similar to the simple UNIX rdate command. This
  * program connects to the default time service port of a specified server, retrieves the time, and prints it to standard output. The default is to use the TCP
  * port. Use the -udp flag to use the UDP port. You can test this program by using the NIST time server at 132.163.135.130 (warning: the IP address may change).
  * <p>

src/main/java/org/apache/commons/net/examples/unix/rlogin.java

@@ -28,11 +28,11 @@
  * writing the remote stdout and stderr to local stdout. If you don't have {@code .rhosts} or {@code hosts.equiv} files set up, the rlogin daemon will prompt
  * you for a password.
  * <p>
- * On Unix systems you will not be able to use the rshell capability unless the process runs as root since only root can bind port addresses lower than 1024.
+ * On UNIX systems you will not be able to use the rshell capability unless the process runs as root since only root can bind port addresses lower than 1024.
  * <p>
  * JVM's using green threads will likely have problems if the rlogin daemon requests a password. This program is merely a demonstration and is not suitable for
  * use as an application, especially given that it relies on line-buffered input from System.in. The best way to run this example is probably from a Windows
- * DOS box into a Unix host.
+ * DOS box into a UNIX host.
  * <p>
  * Example: java rlogin myhost localuser remoteuser vt100
  * <p>

src/main/java/org/apache/commons/net/examples/unix/rshell.java

@@ -27,7 +27,7 @@
  * be executed on the server. It then reads input from stdin (this will be line buffered on most systems, so don't expect character at a time interactivity),
  * passing it to the remote process and writes the process stdout and stderr to local stdout.
  * <p>
- * On Unix systems you will not be able to use the rshell capability unless the process runs as root since only root can bind port addresses lower than 1024.
+ * On UNIX systems you will not be able to use the rshell capability unless the process runs as root since only root can bind port addresses lower than 1024.
  * <p>
  * Example: java rshell myhost localusername remoteusername "ps -aux"
  * <p>

src/main/java/org/apache/commons/net/ftp/FTPFile.java

@@ -389,7 +389,7 @@ public void setUser(final String user) {
     }
 
     /**
-     * Gets a string representation of the FTPFile information. This currently mimics the Unix listing format. This method uses the time zone of the Calendar
+     * Gets a string representation of the FTPFile information. This currently mimics the UNIX listing format. This method uses the time zone of the Calendar
      * entry, which is the server time zone (if one was provided) otherwise it is the local time zone.
      * <p>
      * Note: if the instance is not valid {@link #isValid()}, no useful information can be returned. In this case, use {@link #getRawListing()} instead.
@@ -403,7 +403,7 @@ public String toFormattedString() {
     }
 
     /**
-     * Gets a string representation of the FTPFile information. This currently mimics the Unix listing format. This method allows the Calendar time zone to be
+     * Gets a string representation of the FTPFile information. This currently mimics the UNIX listing format. This method allows the Calendar time zone to be
      * overridden.
      * <p>
      * Note: if the instance is not valid {@link #isValid()}, no useful information can be returned. In this case, use {@link #getRawListing()} instead.

src/main/java/org/apache/commons/net/ftp/parser/EnterpriseUnixFTPEntryParser.java

@@ -22,7 +22,7 @@
 import org.apache.commons.net.ftp.FTPFile;
 
 /**
- * Parser for the Connect Enterprise Unix FTP Server From Sterling Commerce. Here is a sample of the sort of output line this parser processes:
+ * Parser for the Connect Enterprise UNIX FTP Server From Sterling Commerce. Here is a sample of the sort of output line this parser processes:
  *
  * <pre>
  * "-C--E-----FTP B QUA1I1      18128       41 Aug 12 13:56 QUADTEST"

src/main/java/org/apache/commons/net/ftp/parser/UnixFTPEntryParser.java

@@ -25,7 +25,7 @@
 import org.apache.commons.net.ftp.FTPFile;
 
 /**
- * Implementation FTPFileEntryParser and FTPFileListParser for standard Unix Systems.
+ * Implementation FTPFileEntryParser and FTPFileListParser for standard UNIX Systems.
  *
  * This class is based on the logic of Daniel Savarese's DefaultFTPListParser, but adapted to use regular expressions and to fit the new FTPFileEntryParser
  * interface.

src/test/java/org/apache/commons/net/ftp/parser/DefaultFTPFileEntryParserFactoryTest.java

@@ -79,7 +79,7 @@ public void testDefaultParserFactory() {
         parser = factory.createFileEntryParser("AS/400");
         assertTrue(parser instanceof CompositeFileEntryParser);
 
-        // Added test to make sure it handles the Unix systems that were
+        // Added test to make sure it handles the UNIX systems that were
         // compiled with OS as "UNKNOWN". This test validates that the
         // check is case-insensitive.
         parser = factory.createFileEntryParser("UNKNOWN Type: L8");