/title, /particle, /playsound - and possibly other commands - have stopped respecting the "gamerule sendCommandFeedback false" at the server console and logs. In 1.7.x and some early 1.8.x you just set sendCommandFeedback to false and the logs were clean. Now when you are running skripted console commands you get command feedback in logs.

How to reproduce:
Go to console and run:
gamerule sendCommandFeedback false
gamerule logAdminCommands false
gamerule commandBlockOutput false

Login to server with your user, ie. so that you have someone online to run this command on from the Console:

Run from console:
title yourplayername title test

You will get a response in console and logs: "Title command successfully executed" when in fact you would expect to see nothing at all (like it used to be before 1.8.3 or something).

Why is this a problem? I have a script running console commands ~10-20 times/sec. This gives huge amounts of spam in console and logs that is useless information. It makes the log and console unreadable.

Mojang said here that the issue exists and then failed to fix it (and marked it fixed):

https://bugs.mojang.com/plugins/servlet/mobile#issue/MC-82766

Probably fixed in vanilla with command blocks or something but now I need Spigot to fix their end of this. Pretty please? Could you look into this? Please?