August 2016
By Herbert Kaiser

Image: © Mikolette/

Herbert Kaiser is a technical writer, university lecturer and communication trainer. After 15 years of experience in the aerospace business, he has been working independently since 1999. He runs seminars on comprehensive writing and international communication with a special focus on STE.




Writing rules from the ASD-STE100 – an excerpt

Consistent terminology

  • Do not use different Technical Names for the same thing.

Lists instead of long sentences

  • Use a vertical list for complex texts.

Only one thought per sentence

  • Keep to one topic per sentence.
  • Write only one instruction per sentence.

Verbs instead of nouns

  • If there is an approved verb to describe an action, use the verb (not a noun or other part of speech).

Short words/sentences/paragraphs

  • If you have a choice, use the shortest and simplest name.
  • Keep procedural sentences as short as possible (20 words maximum).
  • Keep sentences in descriptive writing as short as possible (25 words maximum).
  • The maximum length of a paragraph is 6 sentences.

Active instead of passive

  • Use the active voice. Use only the active voice in procedural writing, and as much as possible in descriptive writing.

Simple tenses

  • Use the approved forms of the verb to make only:
    - The infinitive
    - The imperative
    - The simple present tense
    - The simple past tense
    - The past participle as an adjective
    - The future tense*

*Author’s note: No other tenses are allowed.

Source: ASD

Simplified Technical English – a globally proven trendsetter

Even 30 years after its initial launch, Simplified Technical English (STE) continues to set itself apart from the bulk of publications on structured/rule-based/controlled writing that have appeared since. So what makes this controlled language so successful?

Enabling unambiguous and readily comprehensible communication across borders, the unique characteristics of STE are strict mandatory rules and simplified English. With this approach, STE has become a trendsetter in tackling the challenges of global communication. Modularized text creation, writing appropriately for human and machine translation, and Augmented Reality are domains in which STE unfolds its full potential.

From poor comprehensibility to KISS

Until the late 1960s, technical documentation was primarily targeted at experts who had to handle high-value machines and equipment. These users usually received internal design and development documents, often in addition to special training. Even consumer goods were commonly accompanied by documentation that had not been specifically adapted to customers. Although industrial products as well as consumer goods became more and more complex in the course of time, technical documentation remained a neglected by-product of development resulting in dire consequences: comprehensibility issues, product damage and accidents.

Something had to be done. An important principle was identified when creators and readers got together to find out where and why things were going wrong, and how technical communication could be improved: KISS = Keep it short and simple. Technical information must be conveyed in a short and simple form, so that users can understand and implement it correctly. This principle still applies today and will not lose its importance in technical communication. However, the KISS motto leaves its implementation to the motivation and experience of the authors. In the long run, this wasn’t good enough, and it became necessary to formulate this maxim more specifically and to derive guidelines/rules for writing.

From KISS to rule-based writing

Intensive research in comprehensibility was conducted and aspects such as target group, readability and comprehensibility were scientifically studied at the text, sentence and word level. The results of these studies clearly confirmed the KISS principle: Technical information that is short and simple is better understood by users.

The first step was to identify the “junk” that still plagues us in free-style texts: inconsistent terminology, long sentences, ambiguous sentences, complex tenses, etc. Then, specific rules were established to counter these evils, such as:

  • Consistent terminology
  • Lists instead of long sentences
  • Only one thought per sentence
  • Verbs instead of nouns
  • Short words/sentences/paragraphs
  • Active instead of passive
  • Simple tenses

When these rules are applied consistently, we obtain good, comprehensible texts. So, how can we connect this rule-based writing with the challenges of global communication?

Global communication in English…

Two scenarios determine global communication: external communication and internal communication.

External communication – user documentation – is the direct communication with the end user. It must be comprehensible across borders, so that the message can be implemented directly and safely. Therefore, many organizations from non-English speaking countries forego expensive translations into regional languages and communicate information about their products and services directly in English.

Internal communication is gaining importance in our networked world. Various divisions of a multinational group must exchange information across the globe at expert level, i.e. several nations and languages are involved. As a result, they use English as the group language.

But is this enough to ensure smooth communication? What must we as technical communicators consider for our English-speaking target group when treating English as a "global language"?

…is the English of non-native speakers

Here are some facts: The ratio of English non-native speakers to native speakers is increasing dramatically and has reached 5:1, see Fig. 1. Moreover, about 70 percent of business communication between non-native speakers is conducted in English. Consequently, "global communication in English is the English of non-native speakers." Therefore, the key question for us is how to reach our target group, the non-native speakers?

Figure 1: Non-native English speakers vastly outnumber native speakers.
Source: Herbert Kaiser


The idiomatic, synonym-rich English of native speakers we learned in school does not fulfill this purpose. When it is about conveying facts and correlations unambiguously and clearly, we must switch to simple English that non-native speakers can understand and implement instantly.

"No native speakers, please"

Employees of global players with English as the group language experience the following situation time and again: The communication between non-native speakers is excellent with simple English, but falters when native speakers enter the discussion. Non-native speakers are often overtaxed by the language level and expressions of native speakers and prefer a simplified form of English. This happens to the extent that a request for "no native speakers, please" is expressed as a precaution when clarifying questions or technical issues.

Particularly in a time when Asia is emerging massively as a global cooperation partner, all partners of a company must become aware of this communication blocker. This is also an important advantage to avoid embarrassment and losing face.

Simplified English

The lowest common denominator for the required English must be a simplified but correct English that can be understood internationally and is oriented towards technical communication. Consequently, rule-based writing and simplified English are the primary components of efficient global communication.

Simplified Technical English (STE)

Rule-based writing and simplified English – STE covers both components. STE is focused on the international comprehensibility of non-native speakers: The basic philosophy of Simplified Technical English is to keep texts as simple and readable as possible. It is possible to convey every complex technical matter in simple words with STE. The specification for STE, the ASD-STE100, is a user-friendly language standard with binding writing rules and a consistent dictionary.

The principles of rule-based writing are reflected in 65 simple specific writing rules. These are not mere recommendations (as they are in other rule systems), but binding mandatory rules. While we find formulations such as "It is recommended to use…" or "Try to avoid…" in conventional style guides, the ASD-STE100 has clear statements such as "Do not use…”

Less is more

Consistent documentation has the highest customer priority and must be considered during content creation. The strict, mandatory rules of STE reduce the degree of freedom and thus the number of inconsistent text variants. Even if several authors work on a complex project, high text consistency is obtained. This is the most important argument considering modular text creation.

No ing-form

STE is more rigorous than any other standard – and that’s a good thing. One specific rule has had the strictest impact on free-style writing: "Do not use the ‘-ing’ form of a verb unless it is part of a Technical Name." All ing-forms are prohibited in STE texts, unless they are technical terminology, e.g. switching relay. Let’s find out why.

When we look at the grammatical function of the ing-form, its ambiguity becomes clear immediately:

  1. The time duration is not specified (ongoing action, future action, etc.)
  2. It can occur in different parts of speech as verb/noun/adjective: "Flying planes can be dangerous".
  3. Frequently, its position in the sentence is ambiguous: "The converter transmits a signal to the processor, starting the test mode of the analyzer". Who triggers the test mode? The converter, the signal or the processor?
  4. Its main function is particularly counterproductive, because it connects various thoughts "elegantly" with each other, which can only be achieved by long sentences. Two rule-based writing sins in one word.

Thus, there is no reason to keep the ambiguous ing-form in technical documentation. However, this rule alarmed language aestheticians the most. They denoted this methodical approach as impractical and inappropriate: "It doesn’t sound as beautiful and fluid as before…" But we, as communication experts, argue quite differently:"If your goal is to write a novel, this is not your job."

Unambiguous global communication is only possible by means of strict rules. However, the area of application of STE is naturally limited. Consciously ambiguous or associative text with flowery language rich in synonyms cannot be created with STE.

Actually, more and more professional writers are becoming aware of the ambiguity of the ing-form. Also native speakers have been sensitized and are dealing constructively with the pros and cons. This can be seen in blog entries of professional writers, such as "Death of the gerund in technical documentation". In the meantime, even clients are requesting their service providers to avoid the ing-form.

STE – a trendsetter for other rule systems

The pragmatic and trendsetting approach of STE also becomes apparent in other cases. The first STE specification appeared in 1986, when structured/rule-based writing was almost unknown. However, today its key values (e.g. the maximum number of words in sentences) are also reflected in other known style guides, which appeared only much later, e.g. J. Kohl’s Global English Style Guide or the Microsoft Manual of Style.


And what is the dictionary good for?

Conventional guidelines and style guides include, for example, a rule that because and since must not be used synonymously as causal conjunctions. In the ASD-STE100, such functionalities are not defined in the rules, but in its dictionary. According to the basic principle of STE One word = one meaning, entries are defined clearly with their approved meaning and their scope of use (see Table 1).

In addition, the NOTE directly guides the author onto the right track for since: "Use since only for temporal progression and think again whether you don’t mean because." All entries in the dictionary include clear and detailed examples that illustrate the correct usage. Simple and user-friendly – a true help for authors.


(part of speech)

Approved meaning/


Not approved


As a result of


SINCE (con)

Function word that shows: “from some time in the past until a later time or now”

NOTE: For other meanings, use BECAUSE.



Since Alodine is a dangerous material, be careful when you use it.

Table 1: Example of a dictionary entry
Source: ASD


Fit for machine translation (MT)

Structured/rule-based texts provide a perfect foundation for translation, all the more so when MT is used. Google Translate is certainly not the answer in the area of MT. In fact it is rather known for its involuntary and strange translation results. Nevertheless, it is used more and more frequently to obtain informative translations for the rough content of a text.

However, when fed with STE texts, Google Translate shows a completely different reaction (this is true at least for German). It often generates good translations that need little editing. Thus, economical machine translation without major post-editing is no longer wishful thinking. Cost reduction in spite of increasing translation requirements – a demand presented by growing globalization – can be realized with STE.

Fit for Augmented Reality (AR)

Currently, in many organizations, Augmented Reality (AR) and mobile technical communication are still visions of the future. However, user information and work instructions via tablet or smart glasses will be a part of our normal life in the foreseeable future. Presenting information precisely and comprehensibly in the smallest restricted space is the ultimate challenge.

The brevity, conciseness and simplified language of STE texts are naturally ideal for such a scenario. But even with regard to the design of safety instructions, STE is far ahead of other style guides. STE principles do not correspond to the usual standards, e.g. ANSI Z535, but are more pragmatic and efficient for technical communication. The signal words WARNING or CAUTION are not followed by long explanations about the type and source of the danger and/or possible consequences of not following the instructions. The first information is always a clear request for user action about what needs to be done or what needs to be avoided. Rule 7.1 of the ASD-STE100 states: "Start a warning or a caution with a simple and clear command."

Safety first

Such pragmatic sequencing of information is critical for AR. On a limited display space, readers might not be able to clearly distinguish between pure information and instructions for action. Consequently, the instructions (commands) or conditions to avoid a danger must be shown at the beginning. Even ANSI Z535 uses this principle; however, here it only refers to warning signs that demand immediate action. This might change in the future. The ASD-STE100 has already influenced many other standards and style guides.

STE – only for the aerospace industry?

Unfortunately, this incorrect contention continues to haunt some minds. Let us take a look at the industries that requested the ASD-STE100. Figure 2 shows that the highest interest in using STE does not come from the core areas of aerospace/defense but from other fields of technology. The huge bandwidth (see Figure 3) supports what professionals have known for 30 years: STE can be used for EVERY field of technology.

Figure 2: Most requests for the ASD-STE100 come from sources other than the aerospace/defense industry.
Source: ASD, Herbert Kaiser


Figure 3: Industries that want to benefit from STE
Source: ASD, Herbert Kaiser

STE – a benefit for all

Clear, easy-to-understand and safe communication of technical content is the task of Simplified Technical English. It has been tried and tested as a mature and trendsetting language standard in global communication, especially for the large target group of non-native speakers. Even existing style guides can be optimized using STE rules, so that all involved can profit: authors, readers/users and the organization. This is the reason why STE has been labeled "the most widely used controlled language on the planet."