The Fine Line in Identical and “Indistinguishably Similar” Trademarks: Invalidity Actions (Industrial Property Code Art. 5(1)(ç) and Its Application)

1) What Do “Identical” and “Indistinguishably Similar” Mean?

SMK Art. 5(1)(ç) expresses the absolute grounds for refusal regime that prevents the registration of signs that are “identical” or “indistinguishably similar” to an earlier registered (or filed) trademark, in respect of the same or the same type of goods/services. In the case of “identicalness” (identity), the signs are identical; in such a scenario, the debate on likelihood of confusion can often operate almost like a presumption, and an in-depth similarity analysis may not be necessary.

By contrast, “indistinguishable similarity” refers to the possibility that—despite some differences—those differences remain so negligible, in terms of the overall impression left on the relevant consumer group, that the signs may be “perceived as if they were the same sign.” In the document, this threshold is constructed in a manner consistent with the approach of the TÜRKPATENT Trademark Examination Guidelines.

The critical practical consequence of this concept is the following: what is required is an objectively “indistinguishable” degree of closeness that goes beyond mere “similarity.” Indeed, it may be said that the Court of Cassation (Yargıtay) tends to interpret SMK Art. 5(1)(ç) narrowly; otherwise, the “likelihood of confusion” territory under SMK Art. 6/1 could be unnecessarily absorbed into the absolute grounds for refusal, making branding more difficult.

2) The Concept of “Similarity”

In practice, the same factual matrix may be debated on two different normative planes. SMK Art. 5(1)(ç) is an absolute ground for refusal; such grounds are, as a rule, considered ex officio. By contrast, SMK Art. 6/1 is a relative ground for refusal and is systematically triggered upon opposition; here, a holistic analysis is carried out by evaluating, together, not only the similarity of the signs but also the identity or similarity of the goods/services, including the likelihood of confusion (including the likelihood of association).

Accordingly, under SMK Art. 5(1)(ç), the “indistinguishably similar” threshold seeks a sharper degree of proximity than the debates on likelihood of confusion, whereas under SMK Art. 6/1 the assessment is conducted within a broader framework of confusion/association.

3) How Do Courts Measure Similarity? “Overall Impression” and the Three-Part Test

The methodological backbone of the Court of Cassation’s trademark similarity analysis is the visual–aural–conceptual examination, followed ultimately by a holistic assessment through “overall impression / general impression.” In its decision dated 04.10.2022, the General Assembly of Civil Chambers (HGK) expressly formulates this approach: alongside visual, aural, and conceptual elements, what matters in similarity is the impression that the signs, as a whole, create in the eyes of consumers.

3.1 Visual Similarity

In visual analysis, elements that are captured “at first glance” come to the fore, such as typeface, figurative components, color scheme, letter sequence, and positioning. In a decision dated 25.03.2019, the 11th Civil Chamber also emphasized that the initial and beginning parts of marks are the salient elements that draw consumer attention.

3.2 Phonetic (Aural) Similarity

Phonetic assessment is conducted through the manner in which the marks are pronounced by the average consumer. In the dispute between “SUSHI TO GO” and “PIZZA 2 GO,” it was accepted that the pronunciation of the two marks converged around “TU GO,” and that, when partial visual similarity and conceptual/phonetic identity were evaluated together, there was a risk of confusion (Court of Cassation 11th Civil Chamber, 27.05.2021, 2020/6260 E., 2021/4504 K.).

However, a critical boundary in Yargıtay’s line is this: phonetic similarity alone is not always deemed sufficient; a proximity that supports the picture is also sought on the visual/conceptual plane. Indeed, in comparing “NUA” and “NOĞA,” it was held that the phonetic proximity would not lead to confusion, due to the simple/non-dominant nature of the common sounds and the absence of visual-conceptual similarity (Court of Cassation 11th Civil Chamber, 13.01.2020, 2019/1967 E., 2020/276 K.).

3.3 Conceptual (Semantic) Similarity

Conceptual analysis proceeds through the realm of meaning and associations evoked by the marks. If there is a clear and distinct difference in meaning between marks, this difference may offset visual and phonetic similarity. As a counter-example, in the comparison between “Yemeli Trakya” and “Trakya,” the likelihood of confusion was accepted due to visual and phonetic similarity (Court of Cassation 11th Civil Chamber, 03.02.2021, 2020/1384 E., 2021/803 K.).

4) The “Average Consumer” and the “Association” Threshold: Likelihood of Confusion Analysis

In assessing likelihood of confusion, Yargıtay interprets broadly the phenomenon of “establishing a link between the marks.” The General Assembly (HGK) states that, in likelihood of confusion, what is important is the possibility that consumers may establish a connection between two signs for any reason (Court of Cassation HGK, 13.06.2012, 2012/11-155 E., 2012/376 K.).

Similarly, in a decision dated 03.03.2014, the 11th Civil Chamber indicated that the public’s establishing a link between two marks—even mere “evocation/association”—may be accepted as a sufficient metric for likelihood of confusion (Court of Cassation 11th Civil Chamber, 03.03.2014, 2013/14603 E., 2014/4031 K.).

Consistent with the phrase “including the likelihood of association” in SMK Art. 6/1, this approach encompasses not only “direct confusion” but also indirect scenarios such as an economic link or an impression of the same commercial origin.

5) Similarity of Goods/Services and the Limits of the Nice Classification

In similarity of goods/services, the Nice classification is a starting point, but it is not binding. Factors such as market perception, similar target consumer circles, proximity of needs, substitutability/competition, distribution channels, and being found on the same shelves are concretizing criteria. In its decision dated 05.05.2011, the 11th Civil Chamber expressly listed these criteria and stressed that similarity of goods/services must be assessed within “market reality” (2011/1562 E., 2011/5464 K.).

6) Distinctiveness of the Mark and the Problem of Descriptive Elements

Providing narrower protection to marks with low distinctiveness (descriptive/weak marks) is a visible principle in Yargıtay practice. The assessment that, due to the low distinctiveness of the mark “DERYA,” it did not cause confusion with “DERYA FİNGER” and “KAPTAN-I DERYA” may be cited as an example in this context (Court of Cassation 11th Civil Chamber, 09.09.2019, 2018/3515 E., 2019/5135 K.).

7) The “Dominant Element” Issue: Minor Additions Do Not Always Save the Day

One of the most practical axes in trademark disputes is the distinction between “dominant element” and “secondary element.” The core principle is clearly set out in the document: if the dominant elements of two marks do not share similarity, it becomes difficult to speak of similarity between the marks. In comparing “İkram” with “device + İ&K İstanbul İkram,” it was accepted that there was no resemblance capable of creating confusion at the visual–phonetic–conceptual level, considering the overall design/arrangement/composition (Court of Cassation 11th Civil Chamber, 21.01.2021, 2020/1371 E., 2021/297 K.).

Conversely, in the “TAMEK FRUITY” and “FRUTTİ” dispute, the document notes that the presence of the term “TAMEK” did not eliminate the effects of similarity, and that the likelihood of association was considered inevitable—showing that secondary additions may not be distinguishing in every case.

8) A Single Letter, Short Marks, and the Principle That “There Is No Uniform Formula”

It is possible to say that Yargıtay does not apply an automatic formula to one-letter differences and short marks; rather, it evaluates based on the data of the concrete case. Therefore, categorical approaches such as “a one-letter difference is always confusing” or “a one-letter difference always distinguishes” are not safe.

In the “Yalıpan” and “YAPIPAN” example, confusion was accepted despite a one-letter difference due to visual and phonetic proximity; whereas in the “BRYCE” and “BAYCE” example, it was stated that there was no risk due to conceptual/visual differences. For short marks, it is specifically noted that sometimes a difference in the last letter may be distinctive, while at other times the identity of the initial letters may strengthen the perception of similarity.

9) From the Perspective of a Nullity Action: The SMK Art. 25 Framework, Time Limits, and Exceptions

In nullity actions, SMK Art. 25 allows both absolute and relative grounds for refusal to be asserted judicially. The document states that SMK Art. 5(1)(ç) (“indistinguishably similar”) is positioned as an absolute ground for nullity, while SMK Art. 6/1 (“likelihood of confusion”) is positioned as a relative ground for nullity.

10) Practice Notes: Case Strategy and the Logic of Evidentiary Construction

As practice suggestions, the following may be articulated: in nullity and confusion disputes, it is preferable to construct a coherent evidentiary set rather than relying on a “single argument.” Suggestions include researching not only identical marks but also similar ones; genuinely differentiating the dominant element; creating a holistic differentiation across visual–phonetic–conceptual planes; and checking adjacent classes as well. In litigation/opposition processes, it is more appropriate to address the three similarity criteria together, to construct the “average consumer” profile according to the specific goods/services, to conduct a descriptiveness analysis, and—especially in technical fields—to seek expert input within a limited scope.

Conclusion

Along the axis of SMK Art. 5(1)(ç), “identical” and “indistinguishably similar” signs establish an absolute refusal threshold targeting the system’s “close-to-counterfeiting and copying” area. Yargıtay’s settled approach, while filtering the discussion through the technical three-part test (visual–aural–conceptual), ultimately conducts the final assessment through overall impression and the average consumer standard. For this reason, a successful nullity strategy should rest not only on word/letter comparisons but also jointly on goods/services proximity, level of distinctiveness, dominant element analysis, and market-perception dynamics.