This article explores deep learning models for the automatic identification of registers - text varieties such as news reports and discussion forums - in web-based datasets across 16 languages. Web register (or genre) identification would provide a robust solution for understanding the content of web-scale datasets, which have become crucial in computational linguistics. Despite recent advances, the potential of register classifiers on the noisy web remains largely unexplored, particularly in multilingual settings and when targeting the entire unrestricted web. We experiment with a range of deep learning models using the new Multilingual CORE corpora, which includes 16 languages annotated using a detailed, hierarchical taxonomy of 25 registers designed to cover the entire unrestricted web. Our models achieve state-of-the-art results, showing that a detailed taxonomy in a hierarchical multi-label setting can yield competitive classification performance. However, all models hit a glass ceiling at approximately 80% F1 score, which we attribute to the non-discrete nature of web registers and the inherent uncertainty in labeling some documents. By pruning ambiguous examples, we improve model performance to over 90%. Finally, multilingual models outperform monolingual ones, particularly benefiting languages with fewer training examples and smaller registers. Although a zero-shot setting decreases performance by an average of 7%, these drops are not linked to specific registers or languages. Instead, registers show surprising similarity across languages.

Adaptive gating plays a key role in temporal data processing via classical recurrent neural networks (RNN), as it facilitates retention of past information necessary to predict the future, providing a mechanism that preserves invariance to time warping transformations. This paper builds on quantum recurrent neural networks (QRNNs), a dynamic model with quantum memory, to introduce a novel class of temporal data processing quantum models that preserve invariance to time-warping transformations of the (classical) input-output sequences. The model, referred to as time warping-invariant QRNN (TWI-QRNN), augments a QRNN with a quantum-classical adaptive gating mechanism that chooses whether to apply a parameterized unitary transformation at each time step as a function of the past samples of the input sequence via a classical recurrent model. The TWI-QRNN model class is derived from first principles, and its capacity to successfully implement time-warping transformations is experimentally demonstrated on examples with classical or quantum dynamics.