Subordinate Clauses

A tagged requirement should consist of one or several grammatically complete sentences. Each complete sentence should consist of a main clause and zero or more subordinate clauses. A main clause can form a complete sentence on its own, while a sub-clause cannot. It’s very common to use subordinate clauses in running text, but they have a tendency to sidetrack a reader and make a requirement less clear. They can create misunderstandings, or be used wrongly. Complicated sentences that contain subordinate clauses are not desirable from a clarity point of view. It’s generally better to write a new main clause than use a sub-clause.

Relative sub-clause.

The text contains a relative sub-clause, which is not allowed according to an active rule.

Relative sub-clauses begin with: "who", "which", "that", "what", "whoever" or "whatever".

Sub-clause of reason or cause.

The text contains a sub-clause of reason or cause, which is not allowed according to an active rule.

Sub-clauses of reason or cause begin with: "because", "inasmuch as", "since", "as", or "for".

Sub-clause of purpose.

The text contains a sub-clause of purpose, which is not allowed according to an active rule.

Sub-clauses of purpose begin with: "so that", "in order to", "so as to", "for the purpose of", or "to".

Concessive sub-clause.

The text contains a concessive sub-clause, which is not allowed according to an active rule.

Concessive sub-clauses begin with: "though", "although", "even if", "while", "whereas", or "as".

Sub-clause of result or purpose.

The text contains a sub-clause of result or purpose, which is not allowed according to an active rule.

Sub-clauses of result or purpose begin with: "so that", "in order that", "in order to", "so as to", "for the purpose of", or "to".

Comparison sub-clause.

The text contains a comparison sub-clause, which is not allowed according to an active rule.

Comparison sub-clauses begin with: "as", "like", "the way", "as if", or "as though".

Temporal sub-clause.

The text contains a temporal sub-clause, which is not allowed according to an active rule.

Temporal sub-clauses begin with: "after", "as", "as soon as", "as long as", "before", "directly", "immediately", "the moment", "once", "since", "until", "when", "whenever", or "while".

Specifying system behaviors will most likely force authors to use temporal sub-clauses. A temporal sub-clause can be seen as a condition for the main clause to be true.

Conditional sub-clause.

The text contains a conditional sub-clause, which is not allowed according to an active rule.

Conditional sub-clauses begin with: "unless", "in case", "in the event that", "on condition that", "provided that", or "as long as".

Specifying system behaviors will most likely force authors to use conditional sub-clauses. A conditional sub-clause can be seen as a condition for the main clause to be true.