Clear concerns how readily the connection can be understood.
Some links require almost no explanation.
London and the United Kingdom have an obvious relationship because London is the capital.
The Beatles and Liverpool are strongly associated.
Paris and France have an immediate geographical and political relationship.
Other links are perfectly valid but less obvious.
They may require background knowledge.
They may depend upon an obscure historical event.
They may become visible only after several intermediate steps.
Direct clarity
A direct link is often clear because the relationship is familiar.
London → capital of → United Kingdom
requires little explanation.
Paris → capital of → France
is similarly clear.
The relationship is strong because most readers recognise it immediately.
Visible clarity
Sometimes clarity comes from being able to see the connection physically.
London and Paris are connected by railway.
A passenger can leave one city, travel through the Channel Tunnel and arrive in the other.
That makes the connection unusually tangible.
The infrastructure itself becomes part of the link.
The Channel Tunnel adds another layer because it is not merely a route but a major engineering object with its own history and significance.
So the relationship can be expressed as:
London → railway → Channel Tunnel → Paris
The link is both conceptual and physical.
Structural clarity
Other links are obvious but cannot be travelled in the same way.
London and the United Kingdom are a good example.
London is within the United Kingdom.
It is not possible to travel from London to the United Kingdom in the ordinary geographical sense because London is already there.
The relationship becomes clearer only when we change scale.
We have to Zoom out:
London → England → United Kingdom
or simply:
London ⊂ United Kingdom
The relationship is one of containment rather than movement.
This is an important distinction.
Some links are routes.
Others are hierarchies.
Others are memberships, categories, ownerships, sequences or identities.
Clear therefore asks not merely whether two things are connected, but whether the nature of the connection is immediately intelligible.
Clear does not mean simple
A link can be very clear while still being complex.
London to Paris involves two cities, two countries, railway infrastructure, international borders, the Channel Tunnel and a transport service.
Yet the basic relationship is immediately understandable.
Conversely, two things may be separated by only one obscure historical fact and therefore be near in link distance but unclear to most people.
Near and Clear are therefore separate qualities.