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 Data flow diagrams, also called DFDs or threat modeling diagrams.
 
 ## Goal
-Many people have presented various different ways to craft data flow diagrams over the years.  This is an attempt to both be precise about what this defninition of a "v3 DFD" is, and also to encourage people to think about diagramming techniques themselves as something that, like code, can be specified and evolved over time, and labeled with a version.
+Many people have presented various different ways to craft data flow diagrams over the years.  This is an attempt to both be precise about what this definition of a "v3 DFD" is, and also to encourage people to think about diagramming techniques themselves as something that, like code, can be specified and evolved over time, and labeled with a version.
 
 ### Symbols/Elements used
 
 | Element | Symbol | Discussion |
 |---------|--------|------------|
-| External entity|  <img src ="icons/rectangle.png" width=50 height=50> | A sharp-cornered rectangle. Anything outside your control.  Examples include people and systems run by other organizations or even divisions.  For example, Joe's mobile phone, the Mint data aggregators (assuming you're modeling from a bank's perspective.).  If you're modeling Mint, then the bank's systems would be external entities. 
+| External entity|  <img src ="icons/rectangle.png" width=50 height=50> | A sharp-cornered rectangle. Anything outside your control.  Examples include people and systems run by other organizations or even divisions.  For example, Joe's mobile phone, the Mint data aggregators (assuming you're modeling from a bank's perspective).  If you're modeling Mint, then the bank's systems would be external entities. 
 | Process| <img src ="icons/rounded-rectangle.png" width=50 height=50> | A rounded rectangle.  Any running code, including compiled, scripts, shell commands, SQL stored procedures, et cetera.
 | Data store|  <img src ="icons/cylinder-256.png" width=50 height=50> | A drum. Anywhere data is stored, including files, databases, shared memory, S3, cookies, et cetera.
 | Data flows| <img src ="icons/arrow.png" width=50 height=50> | An arrow. All the ways that processes can talk to data stores or each other.
-| Trust boundary | . . . | A closed shape drawn with a dashed or dotted line. Usually a box.
+| Trust boundary | . . . | A closed shape drawn with a dashed or dotted line to denote difference realms of the level of trust. Usually a box.