Connection Point Operation

[eric_the_red]

I'm trying to figure out how Connection Points really work because they don't seem to have consistent behaviour. Is there a comprehensive document that describes using connection points?

What I assume: a connection point set to 'out' would connect to an 'in'.  Points set to 'in and out' would connect to either.
What I experience: Visio randomyl decides what will connect together and what it won't based on it's mood or the fullness of the moon or some other unwritten rule that Microsoft won't divulge.

I think what really frustrates me is that, without changing anything, I will try to attach to shapes together at their connection points and it won't work, I'll try again and it will work or will eventually work after several tries and it "decides" to connect. It's like trying to convince a toddler to eat their dinner.

What am I missing or is Visio just a piece of ####.

[Surrogate]

I'm trying to figure out how Connection Points really work because they don't seem to have consistent behaviour. Is there a comprehensive document that describes using connection points?

I do not think that in nature there is a Talmud describing the behavior of connection points...
Most likely on the Internet you will find several articles. For example Connection Point Directions & Types

[wapperdude]

Surrogate provides excellent reference.  Following are some supplemental points of information:

http://visguy.com/vgforum/index.php?topic=10026.msg46088#msg46088
http://visguy.com/vgforum/index.php?topic=10068.0:  about hiding connection points
http://visguy.com/vgforum/index.php?topic=8042.msg34733#msg34733:  gluing 2d shape to 2d shape

[wapperdude]

Attached file shows variety basic 2D to 2D gluing situations. 
Legend:
Orange:  base shape to which others are glued.
Single left/right arrow:  shows input & output connectors
Dbl arrow:  both connectors are In/Out (type=2)
Gray shape:  successfully glued to orange
Red shape:  un-successfully glued

[Surrogate]

Following are some supplemental points of information

May be this video can helps?
Please watch it with your language sub-titles...