September 2013
By Herbert Kaiser

Image: © Gennadiy Poznyakov/

Herbert Kaiser is a technical writer, university lecturer and communication trainer who has been working independently since 1999. After his tenure as an officer with the federal armed forces, he studied technical translation/technical communication in Hildesheim and worked in the aviation and aerospace sector for 15 years as a technical writer, as well as project and department head. He works in the areas of technical documentation and technical translation and also conducts seminars for writing and communication, with a focus on Simplified Technical English.


A close look at Simplified Technical English

Many misconceptions exist about Simplified Technical English. It is no wonder that this language standard struggles to become widely accepted outside of the aviation industry, although merely three per cent of its vocabulary refers to this sector. It is time to correct these assumptions.

Global communication is the buzzword of our times. Everyone has the opportunity to communicate in global social networks. On a commercial level, companies would like to establish themselves and market their products worldwide, and different units of a multinational company need to communicate with one another. Efficient communication channels are required for such tasks. Can Simplified Technical English fulfill this function?

The language standard has been applied by global players for 27 years, but continues to lead a niche existence. Why is it not implemented more in other sectors? Could it be due to misleading or false information?

Task of technical writers

As agents between product and customer, technical writers have a unique mission: convey technical information to users crisply and clearly.

If this has to take place on a global level, technical writers require a communication tool to be understood internationally. Technical communication meanwhile, has become aware of rule-based writing or even controlled languages.

Definition of controlled language

The term “controlled language“ is misleading as the word “control” is often put on par with “monitoring”. This misconception has slipped into practice and often causes confusion for users who are not language experts.

It is a very simple matter really: A language is guided by a few rules. You might find this idea expressed in similar terms such as “monitored”, “regulated” or “standardized language”.

The principles of language are based on the insights gained from research into comprehension. Information that is structured according to specific rules and recipient-oriented is understood better by the user.

First attempts were made as early as in the 1930s and 1970s with Basic English and Caterpillar Fundamental English. The most consistent effect has however been achieved by the language standard “Simplified Technical English“(STE) with the specification ASD-STE100 since 1986. The current version (Issue 6) appeared in January 2013 [1].

How STE functions

Especially for people who do not have any experience with STE, the principle is explained with an example from the ASD-STE100. This example is about security instructions as can be found in technical manuals:


In STE this sentence appears as below:


The example shows how the standard works: Not only has the language changed, but the information content as well. This is because the information must be conveyed to the user without disturbing ballast and in a target-group-oriented manner. While the first variant talks of synthetic oil, additives and absorption and has vague formulations such as “allowed“, “to come into contact with“ or “prolonged periods“, the STE variant is crystallized to what the user really needs to know:

  1. Pay attention that oil doesn’t come in contact with your skin.
  2. It is poisonous.
  3. If it comes in contact with your skin it can cause injury.

This example explains how an abstract matter can be substantiated and translated to relevant information or even instructions for action. This precisely demonstrates the principle and the power of Simplified Technical English: Present the crux of the information and convey it in simple and comprehensible language.

Seven prevalent misconceptions

Unfortunately, misconceptions that don’t correspond to reality are often mentioned during discussions about STE and users become uncertain. So let me scrutinize the seven most prevalent misconceptions and invalidate them with corresponding arguments.

1. Global English and Simplified English

Simplified Technical English, Global English and Simplified English are often mentioned in the same breath. Many approaches have come up bearing the predicate “Simplified English“. One just has to browse the Web to discover many variants: It is used for language training, in dictionaries or for specific sectors. Religious groups use Simplified English to spread their message internationally in an easy to understand language. The Jehovah’s Witnesses are an example, as they have been publishing the issue of the Watchtower in a Simplified English version since July 2011 [2]. The predicate “Global English” is a similar case, which also stands for many different recommendations for simplifying the English language.

Clear differentiation is required here. Even if these different approaches are reasonable, they must not be equalized with the standard “Simplified Technical English“. Some of the confusion about these different terms is owed to the fact that STE came into the market in 1986 as “Simplified English“ and this name is still etched in the minds of many.

We must be clear on this: Only STE as per ASD-STE100 specifies binding mandatory rules with the corresponding consequences for authors. Because it is only in this way that the complete potential of this standard is achieved.

The more individual freedom or optional rules are assigned to the author, the broader his writing options. This in turn has consequences for the reader: Consistency is lost and with it the comprehensibility.

2. Only for aviation

It is correct that the aviation industry developed Simplified Technical English. However, only about three per cent of the vocabulary in the dictionary is specific to aviation. Since the specification came about from the general insights gained from the research into comprehensibility, it is suitable for every type of technical documentation. Many definitions and examples of application have since been extended to general technical areas. In any case, the rules for writing can be used for any industrial branch.

We often overlook the fact that the standard does not prescribe any specialized terminology. It is defined solely by the project. Thus every branch of industry can use its special technical terminology. The general applicability is however just becoming known to companies.

3. Simplify translation

The fact is: STE was developed to avoid translations. It can be understood so clearly from its structure and word selection that users with minimal knowledge of English understand this technical information immediately and can implement it exactly.

Naturally, translations are simplified by the rule-based methodology of the standard, because translation memories can be used much more efficiently. This is an additional positive side effect. If Simplified Technical English is used exclusively to simplify translations, a large part of the overall potential of this language standard will go unutilized.

4. Only for the big guns

Due to the history, the standard is predominantly used for multinational projects of large groups. But what is stopping smaller companies from using STE and gaining better comprehensibility internationally? This is probably due to the following misconception.

5. Too complex, too difficult

After working for 27 years my experience is: every author with technical expertise and good technical English can learn STE with professional training within a short time and apply it.

The standard is structured in classic form according to the principles of a controlled language: Dictionary + Writing Rules.

The dictionary specifies permitted general words with which texts must be built – an example for this is the table below.

Extract from a page of the ASD-STE 100 dictionary

(part of speech)

Approved meaning/


Not approved

acceptance (n)



Before acceptance of unit, carry out the
specified test procedure.


The ability to go into or near



accessible (adj)



Rotate the cover until the jacks marked by + and - are accessible.


An occurrence that causes injury or damage



Source: ASD, Brussels


The principle becomes clear at first glance: Everything in capital letters is permitted in Simplified Technical English; words that are not permitted are shown in small letters.

An explanation of the four columns:

  1. Keyword (part of speech): This is the keyword entry with information on the type of word, because every permitted word in STE is permitted only as a specific word type. E.g. “test“ is only permitted as a noun (the test), but not as verb (to test). Note: Even if the word “acceptance” is marked as not permitted on the example side, it can be used in STE, when it is part of the specific company terminology, e.g. as “acceptance criteria“.
  2. Approved meaning/ALTERNATIVES: This contains the definition of a permitted word, in this case for ACCESS and ACCIDENT. Alternatives or rephrasings are given for words that are not permitted in STE. These are listed in small letters (acceptance and acceptable).
  3. APPROVED EXAMPLE: The entire text in this column is written in capital letters. This indicates that everything conforms to STE. These are sample sentences from technical manuals for the keywords displayed in column 1. If the keyword shown in column 1 is not permitted in STE (small letters), this column has sample sentences with the alternatives provided in column 2 (capital letters).
  4. Not approved: This also deals with sample sentences from technical manuals. But the small letters indicate that the sentences do not conform to STE. The column is only filled for keywords that are not permitted. Column 4 remains empty in case of words conforming to STE.

The dictionary has about 850 permitted words. However, it is made up of a total of about 270 pages, since the largest section is made up of words that are not permitted and their rephrasing with examples as help for the authors.

Writing rules

Since STE was developed from insights gained from the research on comprehensibility, it has many practical standard rules that were included in this specification 27 years ago, including

  • Consistent terminology
  • Lists/enumerations instead of complicated flowing text
  • Correct categorization of safety instructions

Special STE-rules

There are also special rules that define the mechanism of STE, including

  • Limited sentence length
  • No “-ing form“ of verbs
  • No “vague” auxiliary verbs
  • Simple tenses

This language standard was a trendsetter right from its first appearance and its methodology is practical and current. This is proven by the ever-increasing number of style guides, guidelines and manuals for technical writing in the market that have incorporated these rules or have modified them. Unfortunately the rules are only given as recommendations in these guidelines for the most part and not as binding mandatory rules like in the ASD-STE100. This substantially reduces their degree of impact.

6. Software is a prerequisite

Discussions around Simplified Technical English continue to include the point that it doesn’t function without software. Belief in tools shouldn’t however mislead us into assuming that STE can be achieved with the click of a button. The standard was developed 30 years ago when such tools were not thought of due to the minimal computing capabilities. This is exactly where the advantage lies: The language standard is structured so simply and is so comprehensible that software is not necessarily required.

Naturally, tools can support us in our work but there are no check algorithms that consider the most important check point: the semantics. The committee “Simplified Technical English Maintenance Group“, STEMG, has already taken a stand on that. The committee takes care of the further development of the ASD-STE100: “THE BASIC QUESTION FROM STE USERS: Do we need a software product to write in STE correctly? THE STEMG ANSWER: NO. Software will not think in your place. Software does not replace the STE specification. “[3]

Sound knowledge and working with absolute assurance with the specification are the most important prerequisites for mastering and applying STE. This can be achieved only through practical training with professional feedback for the authors.

7. Impact on the author

Some translators and native English speakers take exception to the fact that rule-based texts sound “too simple” and would insult their language aesthetics. References are made that the author formulates monotonously through STE and is less creative. Here too it is necessary to differentiate clearly, since we must remember and realize time and again that we want to write in a way that is appropriate for the target group.

„If your goal is to write a novel, this is not your job“– this guideline continues to be true for technical documentation. Technical contents are to be conveyed in brief, clearly and unambiguously with STE. The area of use is consciously limited.

Ambiguous or associate texts with flowery language and generous use of synonyms or even advertising texts cannot and should not be created with STE. Instead, we get clear and safe texts through the standard that the user can directly implement and that prevent subsequent questions, wrong operation or accidents.

Experience shows that STE has a completely positive impact on the author. Anyone working intensively with the language standard is encouraged by the rule system to follow a way of structured thinking and to translate this in the text.

The author must express his thought and information as per the rule system/dictionary with few permitted words and binding rules, and therefore must work with the greatest creativity. To convey the content to the user clearly and certainly, it must be crystallized and free from ballast.

Quality and savings potential

Clear, easy to understand and safe communication of technical content - that is the task of Simplified Technical English. This applies to external global communication, product communication for the users as well as to internal global communication, i.e. from different partners/units of multinational firms amongst each other.

STE has proven itself as a mature and consistent standard. Even existing style guides can profit from this language standard that has been tried and tested in practice by adapting to the rules. When STE is used correctly, it provides a company with all the advantages of standardization: Uniformity, increase in productivity and cost savings. To summarize:

  1. Proven standard tried and tested in practice
  2. Binding MANDATORY rules
  3. Texts in STE are consistent
  4. Texts in STE are easy to understand internationally even for users with little knowledge of English
  5. STE makes translations easier
  6. STE may make translations superfluous  

Further reading






The history of Simplified English

Three important milestones mark the development of controlled language in the industrial community.

Basic English: It was developed in the 1930s and introduced to enable simplified understanding in international trade within the British colonies. The then standard contained 850 words and few simple rules for grammar/sentence formation. The approach was not followed up further due to the political situation.

CFE (Caterpillar Fundamental English): At the beginning of the 1970s the company Caterpillar introduced the so-called “Caterpillar Fundamental English”, “CFE“ in short. The controlled language emerged from the wish to save on translation costs. A total of over 20,000 publications would have to be translated in 50 different languages and maintained further, an expensive proposition. Since no other method presented a true alternative, this step was decided on and was implemented successfully.

Simplified Technical English (ASD-STE100): The aviation and aerospace industry has always been an innovative branch that was dependent on international communication from early in the day. Before the dominating global players developed, a number of different manufacturers and suppliers had to cooperate with each other. Since English has always been the language of international aviation, it was natural that it was also used for the standard as a common language. Moreover the maintenance and repair documentation had to be written in a language that could also be understood clearly by people whose knowledge of English was not that good. This is extremely important mainly in the areas related to safety in aviation.

Thus, the project for a controlled language for aviation was initiated in the 1980s under the leadership of AECMA, the European Association of Aerospace Industries. Large amounts of existing material was analyzed with enormous efforts in the development phase and insights from the research on comprehensibility were included.

This gave rise to the specification for “Simplified English“, published for the first time in 1986.

The AECMA was reorganized as ASD (Aerospace and Defence Industries Association of Europe). Publishing the most important international specification for creating interactive technical documentation, the S1000D, is one of its responsibilities.

To separate it from other approaches by the same name, Simplified English was renamed to “Simplified Technical English “(STE) in the following issues. The current version 6 was published in January 2013. In the meantime, STE has proven to be a mature and consistent standard that serves as a model for style guides, guidelines or instruction manuals for technical writing.


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#3 Scott Beveridge wrote at Wed, Dec 16 answer

This is a useful and informative overview. Thanks.

In your example from the dictionary I wondered why "access" wasn't even more simply used as a verb, which would result in:


In addition, the word "turn" could be misconstrued, though I guess it depends on context: It is also possible to turn something over. I am sure this has all been thought through carefully as the standard developed.

#2 Orlando Chiarello wrote at Thu, Sep 05 answer homepage

Congratulations and thank you for this excellent article.


ASD and the STEMG fully support the statement about softtware.


As Mike Unwalla said in his comment, software is useful but not strictly necessary.


STE checkers should only be seen as aids for those authors/editors with a good knowledge of STE.


None of these checkers will write STE text for the authors. Nor can they fully convert non-STE text to STE or replace the specification in any way. Although STE checkers can be helpful with highlighting non-STE terms and incorrectly written STE text, they are not foolproof.


No checker has 100% accuracy and there is no software that guarantees 100% compliance with STE.


The STEMG recommends that users always gain experience in writing STE directly before they start using STE tools or software.


The authoring tools can be useful only at the end of the writing process where the authors/editors (not the checker) must have the last word.


Orlando Chiarello - Chairman of the ASD STEMG

#1 Mike Unwalla wrote at Sun, Sep 01 answer homepage

Thank you for an excellent article.


You wrote: The language standard is structured so simply and is so comprehensible that software is not necessarily required.


I agree that software is not necessary. However, software is very useful.


The STE rules are simple. However, the specification contains many thousands of terms (keywords). To remember all the rules for all the terms is difficult. For example, is the term 'fluid' approved? If 'fluid' is approved, is it a noun, an adjective, or both?


Without software, a writer must frequently refer to the specification to make sure that a term is used correctly.