What is an *envelope*?

Reflects the changes in value for a specified parameter (volume, for example) over a period of time. Also refers to the graph of the change—same as vector

ENVELOPE

An envelope is a small, rectangular container made of paper which is ideal for enclosing such things as: marriage proposals to Kate Bush, heartfelt apologies to Kate Bush, renewed marriage proposals to Kate Bush and all of the paperwork surrounding court summonses and restraining orders. They are often kept in small wooden boxes with photos of Kate Bush glued to them. 

Do I detect Sharke has a thing for small wooden boxes?

Karyn
Do I detect Sharke has a thing for small wooden boxes?

Can't stand the things!

sharke
An envelope is a small, rectangular container made of paper which is ideal for enclosing such things as: marriage proposals to Kate Bush, heartfelt apologies to Kate Bush, renewed marriage proposals to Kate Bush and all of the paperwork surrounding court summonses and restraining orders. They are often kept in small wooden boxes with photos of Kate Bush glued to them. 

And she's married ... weird! And has been for some time ... but I can see the ... in the early 80's! Now for a DVD, please!
 

Moshkito

sharke
An envelope is a small, rectangular container made of paper which is ideal for enclosing such things as: marriage proposals to Kate Bush, heartfelt apologies to Kate Bush, renewed marriage proposals to Kate Bush and all of the paperwork surrounding court summonses and restraining orders. They are often kept in small wooden boxes with photos of Kate Bush glued to them. 

And she's married ... weird!

See?  Those envelope thingies must have worked!