Name of the Plugin to replace with "Bla bla bla"

Hello!

I need a plug-in where I can define a set of pairs “key-value”, f. ex.:
<!–my_contacts–> = “Please contact me: My skype: … email: … “
<!–my_text–> = “Bla bla bla”
<!–qwerty–> = “Qwerty”

And so on.

AND when I use any of key (f. ex. <!–my_contacts–>) in my Posts or pages — plugin will automatically , dynamically (on the fly) replace it with appropriate text.

Do you know the name of the plugin that does so ?